FRICTION. Frolling r. normal reaction s

Size: px
Start display at page:

Download "FRICTION. Frolling r. normal reaction s"

Transcription

1 ICTION Introduction If we slide or try to slide a body over a surface, the motion is resisted by a bonding between the body and the surface. This resistance is represented by a single force and is called friction force. The force of friction is parallel to the surface and opposite to the direction of intended motion. Types of riction () Static friction : The opposing force that comes into play when one body tends to move over the surface of another, but the actual motion has yet not started is called static friction. (i) If applied force is and the body remains at rest then static friction =. (ii) If a body is at rest and no pulling force is acting on it, force of friction on it is zero. (iii) Static friction is a self-adjusting force because it changes itself in accordance with the applied force and is always equal to net external force. () Limiting friction : If the applied force is increased, the force of static friction also increases. If the applied force exceeds a certain (maximum) value, the body starts moving. This maximum value of static friction upto which body does not move is called limiting friction. (i) The magnitude of limiting friction between any two bodies in contact is directly proportional to the normal reaction between them. orce of static friction. ut force of maximum static friction is s smax static or (ii) Direction of the force of limiting friction is always opposite to the direction in which one body is at the verge of moving over the other (iii) Coefficient of static friction : (a) is called coefficient of static friction and is defined as the ratio of force of limiting friction and s normal reaction s (b) Dimension : [ M L T ] (c) Unit : It has no unit. (d) Value of depends on material and nature of surfaces in contact that means whether dry or wet ; rough or smooth polished or non-polished. (e) Value of does not depend upon apparent area of contact. (f) Hence the force of limiting friction is a parameter which decides whether the object will slide over or not. It is not always equal to force of friction. (3) Kinetic or dynamic friction : If the applied force is increased further and sets the body in motion, the friction opposing the motion is called kinetic friction. (i) Kinetic friction depends upon the normal reaction. k or k k where k is called the coefficient of kinetic friction (ii) Value of k depends upon the nature of surface in contact. (iii) Kinetic friction is always lesser than limiting friction k l k i.e. coefficient of kinetic s friction is always less than coefficient of static friction. Thus we require more force to start a motion than to maintain it against friction. This is because once the motion starts actually ; inertia of rest has been overcome. lso when motion has actually started, irregularities of one surface have little time to get locked again into the irregularities of the other surface. (iv) Kinetic friction does not depend upon the velocity of the body (provided velocity should not be too large). (v) Types of kinetic friction (a) Sliding friction : The opposing force that comes into play when one body is actually sliding over the surface of the other body is called sliding friction. e.g. flat block is moving over a horizontal table. (b) olling friction : When objects such as a wheel (disc or ring), sphere or a cylinder rolls over a surface, the force of friction that comes into play is called rolling friction. *olling friction is directly proportional to the normal reaction () and inversely proportional to the radius (r) of the rolling cylinder or wheel. rolling r r l s mg

2 r is called coefficient of rolling friction. It would have the dimensions of length and would be measured in metre. * olling friction is often quite small as compared to the sliding friction. That is why heavy loads are transported by placing them on carts with wheels. * In rolling the surfaces at contact do not rub each other. * The velocity of point of contact with respect to the surface remains zero all the times although the centre of the wheel moves forward. Graph etween pplied orce and orce of riction () art O of the curve represents static friction ( s ) increases linearly with the applied force. Its value () t point the static friction is maximum. This represent limiting friction ( l ). (3) eyond, the force of friction is seen to decrease slightly. The portion C of the curve represents the kinetic friction ( k ). O (4) s the portion C of the curve is parallel to x-axis therefore kinetic friction does not change with the applied force, it remains constant, whatever be the applied force. ngle of riction ngle of friction may be defined as the angle which the resultant of limiting friction and normal reaction makes with the normal reaction. y definition angle is called the angle of friction l tan tan = s [s we know l ] or tan ( L ) Hence coefficient of static friction is equal to tangent of the angle of friction. esultant orce Exerted by Surface on lock In the above figure resultant force S S ( mg) ( mg ) S mg when there is no friction ( 0) S will be minimum i.e. S = mg Hence the range of S can be given by, mg S mg ngle of epose ngle of repose is defined as the angle of the inclined plane with horizontal such that a body placed on it is just begins to slide. mg sin y definition, is called the angle of repose. In limiting condition mg sin and mg cos So tan s tan tan tan s ] Thus the coefficient of limiting friction is equal to the tangent of angle of repose. s well as i.e. angle of repose = angle of friction. Calculation of equired orce in Different Situation If W = weight of the body, = angle of friction, tan coefficient of friction Then we can calculate required force for different situation in the following manner : () Minimum pulling force at an angle from the horizontal y resolving in horizontal and vertical direction (as shown in figure) or the condition of equilibrium cos and W sin s orce of friction s l pplied force S k mg sin W mg C mg cos cos

3 y substituting these value in cos ( W sin) sin cos ( W sin) [s tan ] cos sin W cos( ) () Minimum pushing force at an angle from the horizontal y esolving in horizontal and vertical direction (as shown in the figure) or the condition of equilibrium cos and W sin y substituting these value in cos ( W sin) sin cos ( W sin) [s tan ] cos sin W cos( ) (3) Minimum pulling force to move the body up on an inclined plane y esolving in the direction of the plane and perpendicular to the plane (as shown in the figure) + sin cos sin W cos + W sin W W cos or the condition of equilibrium sin W cos W cos sin and W sin cos cos W sin y substituting these values in and solving we get sin ( ) W cos( ) (4) Minimum force to move a body in downward direction along the surface of inclined plane + sin cos + W W cos y esolving in the direction of the plane and perpendicular to the plane (as shown in the figure) or the condition of equilibrium sin W cos W cos sin and cos W sin y substituting these values in and solving we get sin( ) W cos( )

4 (5) Minimum force to avoid sliding of a body down on an inclined plane + sin + cos W sin W cos W y esolving in the direction of the plane and perpendicular to the plane (as shown in the figure) or the condition of equilibrium sin W cos W cos sin and cos W sin W sin cos y substituting these values in and solving we get sin ( ) W cos( ) (6) Minimum force for motion along horizontal surface and its direction + sin Let the force be applied at an angle with the horizontal. y resolving in horizontal and vertical direction (as shown in figure) or vertical equilibrium sin mg mg sin (i) and for horizontal motion cos i.e. cos (ii) Substituting value of from (i) in (ii) cos ( mg sin) mg (iii) cos sin or the force to be minimum (cos sin) must be maximum i.e. d [cos sin ] 0 d sin cos 0 tan or tan ( ) angle of friction i.e. or minimum value of its angle from the horizontal should be equal to angle of friction s tan so from the figure, sin and cos y substituting these value in equation (iii) mg mg min mg mg cos

5 cceleration of a lock gainst riction () cceleration of a block on horizontal surface When body is moving under application of force, then kinetic friction opposes its motion. Let a is the net acceleration of the body rom the figure ma k k a m () cceleration of a block sliding down over a rough inclined plane When angle of inclined plane is more than angle of repose, the body placed on the inclined plane slides down with an acceleration a. rom the figure ma mg sin ma ma mg sin ma mg sin mg cos mg sin cceleration a g [sin cos ] mg mg cos Note : or frictionless inclined plane 0 a g sin. (3) etardation of a block sliding up over a rough inclined plane When angle of inclined plane is less than angle of repose, then for the upward motion ma ma mg sin mg sin + ma mg sin mg cos mg mg cos etardation a g[sin cos ] Note : or frictionless inclined plane 0 a g sin Motion of Two odies one esting on the Other When a body of mass m is resting on a body of mass M then two conditions are possible () force is applied to the upper body, () force is applied to the lower body k mg ma m M L We will discuss above two cases one by one in the following manner: () force is applied to the upper body, then following four situations are possible (i) When there is no friction (a) The body will move on body with acceleration (/m). a / m (b) The body will remain at rest a 0 (c) If L is the length of as shown in figure, will fall from after time t L ml t a s s a t and a /m (ii) If friction is present between and only and applied force is less than limiting friction ( < l) ( = pplied force on the upper body, l = limiting friction between and, k = Kinetic friction between and ) (a) The body will not slide on body till i.e. mg (b) Combined system (m + M) will move together with common acceleration l s a a M m

6 (iii) If friction is present between and only and applied force is greater than limiting friction ( > l) In this condition the two bodies will move in the same direction (i.e. of applied force) but with different acceleration. Here force of kinetic friction kmg will oppose the motion of while cause the motion of. i.e. k m a a a k m ( kmg) m ree body diagram of ma k i.e. k M a k a M a k mg M ree body diagram of Ma K Note : s both the bodies are moving in the same direction. cceleration of body relative to will be M k mg ( m M ) a a a mm So, will fall from after time L m ML t a M mg ( m M ) k (iv) If there is friction between and floor (where l ( M m) g = limiting friction between and floor, k = kinetic friction between and ) will move only if k and then l k l M a Ma l K However if does not move then static friction will work (not limiting friction) between body and the floor i.e. friction force = applied force (= k) not. l () force is applied to the lower body, then following four situations are possible (i) When there is no friction (a) will move with acceleration (/M) while will remain at rest (relative to ground) as there is no pulling force on. a and a 0 M (b) s relative to, will move backwards with acceleration (/M) and so will fall from it in time t. t L a ML M L m (ii) If friction is present between and only and < l (where = seudo force on body and l = limiting friction between body and )

7 (a) oth the body will move together with common acceleration a M m (b) seudo force on the body, m ma and l smg m M (c) m l mg s s ( m M ) g m M So both bodies will move together with acceleration a a if s [ m M ] g m M (iii) If friction is present between and only and > l (where l = s mg = limiting friction between body and ) oth the body will move with different acceleration. Here force of kinetic friction kmg the motion of while will cause the motion of. will oppose ma k mg i.e. a k g ree body diagram of ma k k Ma [ kmg ] a i.e. M ree body diagram of Ma K Note : s both the bodies are moving in the same direction cceleration of body relative to will be k g( m M ) a a a M Negative sign implies that relative to, will move backwards and will fall it after time t L a ML g( m M ) k (iv) If there is friction between and floor and > l : (where l = s(m+m)g = limiting friction between body and surface) The system will move only if '' l then replacing by l. The entire case (iii) will be valid. However if the system will not move and friction between and floor will be while between and is zero. Motion of an Insect in the ough owl The insect crawl up the bowl, up to a certain height h only till the component of its weight along the bowl is balanced by limiting frictional force. O l r y mg cos mg mg sin h Let m = mass of the insect, r = radius of the bowl, = coefficient of friction for limiting condition at point mg cos...(i) and l mg sin...(ii) Dividing (ii) by (i)

8 tan l s l r y y or y r So h r y r, h r Minimum Mass Hung from the String to Just Start the Motion () When a mass m placed on a rough horizontal plane nother mass m hung from the string connected by frictionless pulley, the tension (T) produced in string will try to start the motion of mass m. T l m m g T m t limiting condition m g T l mg mg mg m m this is the minimum value of m to start the motion. Note: In the above condition Coefficient of friction m m () When a mass m placed on a rough inclined plane nother mass m hung from the string connected by frictionless pulley, the tension (T) produced in string will try to start the motion of mass m. t limiting condition or m T mg (i) T or m T m g sin T T mg sin m m T m g sin m g cos (ii) rom equation (i) and (ii) m m[sin cos ] m g sin + m g cos m g this is the minimum value of m to start the motion m g Note : In the above condition Coefficient of friction m tan m cos Maximum Length of Hung Chain uniform chain of length l is placed on the table in such a manner that its l' part is hanging over the edge of table without sliding. Since the chain have uniform linear density therefore the ratio of mass and ratio of length for any part of the chain will be equal. We know m mass hanging from the table m mass lying on the table or this case we can rewrite above expression in the following manner length hanging from the table [s chain have uniform linear density] length lying on the table l ( l l ) l l by solving l l l ( )

9 Coefficient of riction etween a ody and Wedge body slides on a smooth wedge of angle and its time of descent is t. S S Smooth wedge ough wedge If the same wedge made rough then time taken by it to come down becomes n times more (i.e. nt) The length of path in both the cases are same. or smooth wedge, S u t at S ( g sin ) t (i) [ s u 0and a g sin ] or rough wedge, S u t at S g (sin cos )( nt) (ii) [ su 0and a g (sin cos )] rom equation (i) and (ii) ( g sin ) t = g (sin cos )( nt) sin (sin cos ) n tan n Stopping of lock Due to riction () On horizontal road (i) Distance travelled before coming to rest : block of mass m is moving initially with velocity u on a rough surface and due to friction, it comes to rest after covering a distance S. u S v = 0 etarding force ma ma mg a g rom v u as 0 u g S [s v 0, a g] u S or S g m g [s momentum = mu] (ii) Time taken to come to rest rom equation v u at 0 u g t [ s v 0, a g] u t g () On inclined road : When block starts with velocity u its kinetic energy will be converted into potential energy and some part of it goes against friction and after travelling distance S it comes to rest i.e. v = 0. v = 0 We know that retardation a g[sin cos] S y substituting the value of v and a in the following equation u v u a S 0 u g [sin cos ] S

10 u S g (sin cos ) Stopping of Two locks Due to riction When two masses compressed towards each other and suddenly released then energy acquired by each block will be dissipated against friction and finally block comes to rest i.e., S = E [Where = riction, S = Distance covered by block, E = Initial kinetic energy of the block] m m m m S [Where = momentum of block] m mg S [s = mg] m S m g In the given condition and are same for both the blocks. So, S ; S m m S m Sticking of a lock With ccelerated Cart When a cart moves with some acceleration toward right then a pseudo force (ma) acts on block toward left. This force (ma) is action force by a block on cart. S S a ma m M CT m mg Now block will remain static w.r.t. cart. If friction force mg [ s ma] ma mg g a g amin This is the minimum acceleration of the cart so that block does not fall. and the minimum force to hold the block together min ( M m) amin g min ( M m)

11 Understanding Concept:-. Determine the maximum acceleration of the train in which a box lying on its floor will remain stationary, given that the co-efficient of static friction between the box and the train s floor is See ig. mass of 4 kg rests on a horizontal plane. The plane is gradually inclined until at an angle θ = 5 with the horizontal, the mass just begins to slide. What is the coefficient of static friction between the block and the surface? 3. What is the acceleration of the block and trolley system shown in a ig., if the coefficient of kinetic friction between the trolley and the surface is 0.04? What is the tension in the string? (Take g = 0 m s - ). Neglect the mass of the string. 4. Two bodies and of masses 5 kg and 0 kg in contact with each other rest on a table against a rigid wall (ig.). The coefficient of friction between the bodies and the table is 0.5. force of 00 N is applied horizontally to. What are (a) the reaction of the partition (b) the action-reaction forces between and? What happens when the wall is removed? Does the answer to (b) change, when the bodies are in motion? Ignore the difference between μs and μk. 5. block of mass 5 kg is placed on a long trolley. The coefficient of static friction between the block and the trolley is 0.8. The trolley accelerates from rest with 0.5 m s - for 0 s and then moves with uniform velocity. Discuss the motion of the block as viewed by (a) a stationary observer on the ground, (b) an observer moving with the trolley. 6. The rear side of a truck is open and a box of 40 kg mass is placed 5 m away from the open end as shown in ig. The coefficient of friction between the box and the surface below it is 0.5. On a straight road, the truck starts from rest and accelerates with m s -. t what distance from the starting point does the box fall off the truck? (Ignore the size of the box). 7. brick slides on a horizontal surface. Which of the following will increase the magnitude of the frictional force on it?. utting a second brick on top. Decreasing the surface area of contact C. Increasing the surface area of contact D. Decreasing the mass of the brick E. None of the above 8. The coefficient of kinetic friction:. is in the direction of the frictional force. is in the direction of the normal force C. is the ratio of force to area

12 D. can have units of newtons E. is none of the above 9. When the brakes of an automobile are applied, the road exerts the greatest retarding force:. while the wheels are sliding. just before the wheels start to slide C. when the automobile is going fastest D. when the acceleration is least E. at the instant when the speed begins to change 0. forward horizontal force of N is used to pull a 40-N crate at constant velocity across a horizontal floor. The coefficient of friction is: C. D. 0. E. 0. The speed of a 4.0-N hockey puck, sliding across a level ice surface, decreases at the rate of 0.6m/s. The coefficient of kinetic friction between the puck and ice is: C. 0.6 D.. E crate rests on a horizontal surface and a woman pulls on it with a 0-N force. No matter what the orientation of the force, the crate does not move. ank the situations shown below according to the magnitude of the frictional force of the surface on the crate, least to greatest..,, 3.,, 3 C., 3, D., 3, E. 3,, 3. crate with a weight of 50N rests on a horizontal surface. person pulls horizontally on it with a force of 0N and it does not move. To start it moving, a second person pulls vertically upward on the crate. If the coefficient of static friction is 0.4, what is the smallest vertical force for which the crate moves?. 4N. 0N C. 4N D. 5N E. 35N N crate rests on a rough horizontal floor. -N horizontal force is then applied to it. If the coefficients of friction are s = 0.5 and k = 0.4, the magnitude of the frictional force on the crate is:. 8N. N C. 6N D. 0N E. 40N 5. 4-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface. If the coefficients of friction are s = 0.5 and k = 0.4, the magnitude of the frictional force on the block is:. 8N. N C. 6N D. 0N E. 400N 6. horizontal shove of at least 00N is required to start moving a 800-N crate initially at rest on a horizontal floor. The coefficient of static friction is: C D E. none of these 7. force (larger than the largest possible force of static friction) is applied to the left to an object moving to the right on a horizontal surface. Then:. the object must be moving at constant speed. and the friction force act in opposite directions C. the object must be slowing down D. the object must be speeding up E. the object must come to rest and remain at rest 8. bureau rests on a rough horizontal surface (s = 0.50, k = 0.40). constant horizontal force, just sufficient to start the bureau in motion, is then applied. The acceleration of the bureau is: m/s C. 3.3m/s D. 4.5m/s E. 8.9m/s 9. car is traveling at 5m/s on a horizontal road. The brakes are applied and the car skids to a stop in 4.0 s. The coefficient of kinetic friction between the tires and road is: C D. 0.9 E.. 0. boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and g is the magnitude of the force of gravity. Which of the following must be true?. = f and N = g. = f and N >g C. >f and N <g D. >f and N = g E. none of these

13 . boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and g is the magnitude of the force of gravity. Which of the following must be true?. = f and N = g. = f and N >g C. >f and N <g D. >f and N = g E. none of these. 400-N block is dragged along a horizontal surface by an applied force as shown. The coefficient of kinetic friction is k = 0.4 and the block moves at constant velocity. The magnitude of is:. 00N. 50N C. 00N D. 90N E. 400 N 3. block of mass m is pulled at constant velocity along a rough horizontal floor by an applied force T as shown. The magnitude of the frictional force is:. T cos. T sin C. zero D. mg E. mg cos 4. block of mass m is pulled along a rough horizontal floor by an applied force T as shown. The vertical component of the force exerted on the block by the floor is:. mg. mg - T cos C. mg + T cos D. mg - T sin E. mg + T sin 5. -kg crate rests on a horizontal surface and a boy pulls on it with a force that is 30 0 below the horizontal. If the coefficient of static friction is 0.40, the minimum magnitude force he needs to start the crate moving is:. 44N. 47N C. 54N D. 56N E. 7N 6. crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction is To start the crate moving with the weakest possible applied force, in what direction should the force be applied?. Horizontal. 4 0 below the horizontal C. 0 above the horizontal D. 4 0 above the horizontal E below the horizontal N force is applied to a crate on a horizontal rough floor, causing it to move horizontally. If the coefficient of kinetic friction is 0.50, in what direction should the force be applied to obtain the greatest acceleration?. Horizontal above the horizontal C above the horizontal D. 7 0 above the horizontal E below the horizontal 8. professor holds an eraser against a vertical chalkboard by pushing horizontally on it. He pushes with a force that is much greater than is required to hold the eraser. The force of friction exerted by the board on the eraser increases if he:. pushes with slightly greater force. pushes with slightly less force C. stops pushing D. pushes so his force is slightly downward but has the same magnitude E. pushes so his force is slightly upward but has the same magnitude 9. horizontal force of N pushes a 0.5-kg book against a vertical wall. The book is initially at rest. If the coefficients of friction are s = 0.6 and k = 0.8 which of the following is true?. The magnitude of the frictional force is 4.9N. The magnitude of the frictional force is 7.N C. The normal force is 4.9N D. The book will start moving and accelerate E. If started moving downward, the book will decelerate

14 30. horizontal force of 5.0N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. If the coefficients of friction are s = 0.6 and k = 0.80, the magnitude of the frictional force is: N C. 3.0N D. 5.0N E. 4.0N 3. horizontal force of N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. Ifs = 0.6 and k = 0.80, the acceleration of the book in m/s is: m/s C. 9.8m/s D. 4.4m/s E. 9.m/s 3. horizontal force of 5.0N pushes a 0.50-kg block against a vertical wall. The block is initially at rest. If s = 0.60 and k = 0.80, the acceleration of the block in m/s is: C. 6.0 D. 8.0 E heavy wooden block is dragged by a force along a rough steel plate, as shown below for two possible situations. The magnitude of is the same for the two situations. The magnitude of the frictional force in (ii), as compared with that in (i) is:. the same. greater C. less D. less for some angles and greater for others E. can be less or greater, depending on the magnitude of the applied force. 34. block is first placed on its long side and then on its short side on the same inclined plane, as shown. The block slides down the plane on its short side but remains at rest on its long side. possible explanation is:. the short side is smoother. the frictional force is less because the contact area is less C. the center of gravity is higher in the second case D. the normal force is less in the second case E. the force of gravity is more nearly down the plane in the second case 35. box rests on a rough board 0 meters long. When one end of the board is slowly raised to a height of 6 meters above the other end, the box begins to slide. The coefficient of static friction is: C. 0.4 D. 0.6 E block is placed on a rough wooden plane. It is found that when the plane is tilted 30 to the horizontal, the block will slide down at constant speed. The coefficient of kinetic friction of the block with the plane is: C..73 D E crate is sliding down an incline that is 35 0 above the horizontal. If the coefficient of kinetic friction is 0.40, the acceleration of the crate is:. 0..4m/s C. 5.8m/s D. 8.8m/s E.0.3m/s kg crate is resting on a horizontal plank. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is fter one end of the plank is raised so the plank makes an angle of 5 0 with the horizontal, the force of friction is:. 0. 8N C. N D. N E. 44N kg crate is resting on a horizontal plank. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is fter one end of the plank is raised so the plank makes an angle of 30 0 with the horizontal, the force of friction is:. 0. 8N C. N D. N E. 44N kg crate is on an incline that makes an angle of 30 0 with the horizontal. If the coefficient of static friction is 0.50, the minimum force that can be applied parallel to the plane to hold the crate at rest is: N C. 30N D. 46N E. 55N kg crate is on an incline that makes an angle of 30 0 with the horizontal. If the coefficient of static friction is 0.5, the maximum force that can be applied parallel to the plane without moving the crate is: N C. 30N D. 46N E. 55N 4. lock, with mass m, is initially at rest on a horizontal floor. lock, with mass m, is initially at rest on the horizontal top surface of. The coefficient of static friction between the two blocks is s. lock is pulled with a horizontal force. It begins to slide out from under if the force is greater than:. m g. m g C. s m g D. s m g E. s (m +m ) g

15 43. The system shown remains at rest. Each block weighs 0 N. The force of friction on the upper block is:. 4N. 8N C. N D. 6N E. 0N 44. lock, with a mass of 50 kg, rests on a horizontal table top. The coefficient of static friction is horizontal string is attached to and passes over a massless frictionless pulley as shown. The smallest mass m of block, attached to the dangling end, that will start moving when it is attached to the other end of the string is:. 0 kg. 30 kg C. 40 kg D. 50 kg E. 70 kg 45. lock, with a mass of 0 kg, rests on a 35 0 incline. The coefficient of static friction is n attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. The largest mass m of block, attached to the dangling end, for which begins to slide down the incline is:..5kg. 3.5kg C. 5.9kg D. 9.0kg E. 0.5kg 46. lock, with a mass of 0 kg, rests on a 35 0 incline. The coefficient of static friction is n attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. The largest mass m, attached to the dangling end, for which remains at rest is:..5kg. 3.5kg C. 5.9kg D. 9.0kg E. 0.5kg 47. lock, with a mass of 0 kg, rests on a 30 0 incline. The coefficient of kinetic friction is 0.0. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. lock, with a mass of 8.0 kg, is attached to the dangling end of the string. The acceleration of is:. 0.69m/s, up the plane. 0.69m/s, down the plane C..6m/s, up the plane D..6m/s, down the plane E lock, with a mass of 0 kg, rests on a 30 0 incline. The coefficient of kinetic friction is 0.0. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. lock, with a mass of 3.0 kg, is attached to the dangling end of the string. The acceleration of is:. 0.0m/s, up. 0.0m/s, down C..8m/s, up D..8m/s, down E kg airplane moves in straight flight at constant speed. The force of air friction is 800 N. The net force on the plane is:. zero. 800N C. 800N D. 9800N E. none of these 50. Why do raindrops fall with constant speed during the later stages of their descent?. The gravitational force is the same for all drops. ir resistance just balances the force of gravity C. The drops all fall from the same height D. The force of gravity is negligible for objects as small as raindrops

16 E. Gravity cannot increase the speed of a falling object to more than 9.8m/s 5. ball is thrown downward from the edge of a cliff with an initial speed that is three times the terminal speed. Initially its acceleration is. upward and greater than g. upward and less than g C. downward and greater than g D. downward and less than g E. downward and equal to g 5. ball is thrown upward into the air with a speed that is greater than terminal speed. On the way up it slows down and, after its speed equals the terminal speed but before it gets to the top of its trajectory:. its speed is constant. it continues to slow down C. it speeds up D. its motion becomes jerky E. none of the above 53. ball is thrown upward into the air with a speed that is greater than terminal speed. It lands at the place where it was thrown. During its flight the force of air resistance is the greatest:. just after it is thrown. halfway up C. at the top of its trajectory D. halfway down E. just before it lands. 54. In a situation the contact force by a rough horizontal surface on a body placed on it has constant magnitude. If the angle between this force and the vertical is decreased, the force and the vertical is decreased, the friction force between the surface and the body will (a) increse (b*) decrease (c) remain the same (d) may increase or decrease 55. While walking on ice, one should take small steps to avoid slipping. This is because smaller steps to avoid slipping. This is because smaller steps ensure (a) larger friction (b*) smaller friction (c) larger normal force (d) smaller normal force 56. body of mass M is kept on a rough horizontal surface (friction coefficient = ). person is trying to pull the body by applying a horizontal force but the body is not moving. The force by the surface on is where (a) = Mg (b) = Mg (c*) Mg Mg (d) Mg Mg 57. scooter starting from rest moves with a constant acceleration for a time Δt, then with a constant deceleration for the next Δt and finally with a constant deceleration for the next Δt 3 to come to rest. 500N man sitting on the scooter behind the driver manges to stay at rest with respect to the scooter without touching any other part. The force exerted by the seat on the man is (a) 500 N throughout the journey (b*) less than 500N throughout the journey (c) more than 500N throughout the journey (d) > 500 N for time Δt and Δt 3 and 500 N for Δt. 58. Consider the situation shown in figure. The wall is smooth but the surface of and in contact are rough. The friction on due to in equilibrium (a) is upward (b) is downward (c) is zero (d*) the system cannot remain in equilibrium. 59. Suppose all the surfaces in the previous problem are rough. The direction of friction on due to (a*) is upward (b) is downward (c) is zero (d) depends on the masses of and. 60. Two cars of unequal masses use similar tyres. If they are moving at the same initial speed, the minimum stopping distance (a) is smaller for the heavier car (b) is smaller for the lighter car (c*) is same for both cars (d) depends on the volume of the car. 6. In order to stop a car in shortest distance on a horizontal road, one should (a) apply the brakes very hard so that the wheels stop rotating (b*) apply the brakes hard enough to just prevent slipping (c) pump the brakes (press and release) (d) shut the engine off and not apply brakes.

17 6. block kept on an inclined surface just begins to slide if the inclination is 30º. The block is replaced by another block and it is found that it just begins to slide if the inclination is 40º. (a) mass of > mass of (b) mass of < mass of (c) mass of = mass of (d*) all the three are possible. 63. boy of mass M is applying a horizontal force to slide a box of mass M on a rough horizontal surface. The coefficient of friction between the shoes of the boy and the floor is and that between the box and the floor is. In which of the following cases it is certainly not possible to slide the box? (a*) <, M < M (b) >, M < M (c) <, M > M (d) >, M > M 64. Let, N and f denote the magnitudes of the contact force, normal force and the friction exerted by one surface on the other kept in contact. If none of these is zero, (a*) > N (b*) > f (c) N > f (d*) N f < < N + f 65. The contact force exerted by a body on another body is equal to the normal force between the bodies. We conclude that (a) the surface must be frictionless (b*) the force of friction between the bodies is zero (c) the magnitude of normal force equals that of friction (d*) the bodies may be rough but they don t slip on each other. 66. Mark the correct statements about the friction between two bodies. (a) Static friction is always greater than the kinetic friction. (b*) Coefficient of static friction is always greater than the coefficient of kinetic friction. (c*) Limiting friction is always greater than the kinetic friction. (d*) Limiting friction is never less than static friction. 67. block is placed on a rough floor and a horizontal force is applied on it. The force of friction f by the floor on the block is measured for different values of and a graph is plotted between them. (a) The graph is a straight line of slope 45º (b) The graph is straight line parallel to the -axis. (c*) The graph is a straight line of slope 45º for small and a straight line parallel to the -axis for large. (d*) There is a small kink on the graph. 68. Consider a vehicle going on a horizontal road towards east. Neglect any force by the air. The frictional forces on the vehicle by the road. (a*) is towards east if the vehicle is accelerating (b*) is zero if the vehicle is moving with a uniform velocity (c) must be towards east. (d) must be towards east.

18 ICTION {H Series}. body of mass 400 g slides on a rough horizontal surface. If the frictional force is 3.0 N, find (a) the angle made by the contact force on the body with the vertical and (b) the magnitude of the contact force. Take g = 0m/s.. The coefficient of static friction between a block of mass m and an incline is s = 0.3. (a) What can be the maximum angle of the incline with the horizontal so that the block does not slip on the plane? (b) If the incline makes an angle / with the horizontal, find the frictional force on the block. 3. horizontal force of 0 N is applied to a block of mass 4 kg resting on a rough horizontal table. If the block does not moue on the table, how much frictional force the table is applying on the block? What can be said about the coefficient of static friction between the block and the table? Take g = 0m/s. 4. The coefficient of static friction between the block of kg and the table shown in figure is s = 0.. What should be the maximum value of m so that the blocks do not move? Take g = 0m/s. The string and the pulley are light and smooth. ig. 5. The coefficient of static friction between the two blocks shown in figure is µ and the table is smooth. What maximum horizontal force can be applied to the block of mass M so that the blocks moue together? ig. 6. block slides down an incline of angle 30 with acceleration g/4. ind the kinetic friction coefficient. 7. block of mass.5 kg is kept on a rough horizontal surface. It is found that the block does not slide if a horizontal force less than 5 N is applied to it. lso it is found that it takes 5 seconds to slide through the first 0 m if a horizontal force of 5 N is applied and the block is gently pushed to start the motion. Taking g =0 m/s, calculate the coefficients of static and kinetic friction between the block and the surface. 8. block placed on a horizontal surface is being pushed by a force making an angle with the vertical. If the friction coefficient is µ, how much force is needed to get the block just started. Discuss the situation when tan<. 9. ind the maximum value of M/m in the situation shown in figure 3 so that the system remains at rest. riction coefficient at both the contacts is Discuss the situation when tan < µ. ig.3 0. Consider the situation shown in figure 4. The horizontal surface below the bigger block is smooth. The coefficient of friction between the blocks is µ. ind the minimum and the maximum force that can be applied in order to keep the smaller blocks at rest with respect to the bigger block.

19 ig.4. igure 5 shows two blocks connected by a light string placed on the two inclined parts of a triangular structure. The coefficients of static and kinetic friction are 0.8 and 0.5 respectively at each of the surfaces. (a) ind the minimum and maximum values of m for which the system remains at rest. (b) ind the acceleration of either block if m is given the minimum value calculated in the first part and is gently pushed up the incline for a short while. ig.5. If the tension in the string in figure 6 is 6 N and the acceleration of each block is 0.5 m/s, find the friction coefficients at the two contacts with the blocks. ig.6 3. The friction coefficient between the table and the block shown in figure 7 is 0.. ind the tensions in the two strings. ig.7 4. The friction coefficient between a road and the tyre of a vehicle is 4/3. ind the maximum incline the road may have so that once hard brakes are applied and the wheel starts skidding, the vehicle going down at a speed of 36 km/hr is stopped within 5 m. 5. igure 8 shows two blocks in contact sliding down an inclined surface of inclination 30. The friction coefficient between the block of mass.0 kg and the incline is, and that between the block of mass 4.0 kg and the incline is. Calculate the acceleration of the.0 kg block if (a) = 0.0 and = 0.30, (b) = 0.30 and = 0.0. Take g = 0 m/s. ig.8 6. Two masses M l and M are connected by a light rod and the system is slipping down a rough incline of angle with the horizontal. The friction coefficient at both the contacts is. ind the acceleration of the system and the force by the rod on one of the blocks. 7. block of mass M is kept on a rough horizontal surface. The coefficient of static friction between the block and the surface is. The block is to be pulled by applying a force to it. What minimum force is needed to slide the block? In which direction should this force act? 8. The friction coefficient between the board and the floor shown in figure 9 is. ind the maximum force that the man can exert on the rope so that the board does not slip on the floor.

20 ig.9 9. kg block is placed over a 4 kg block and both are placed on a smooth horizontal surface. The coefficient of friction between the blocks is 0.0. ind the acceleration of the two blocks if a horizontal force of N is applied to (a) the upper block, (b) the lower block. Take g=0m/s. 0. ind the accelerations a, a, a 3 of the three block; shown in figure 0 if a horizontal force of 0 N ii applied on (a) kg block, (b) 3 kg block, (c) 7 kg block. Take g=0m/s. ig.0. The friction coefficient between the two blocks shown it y figure is but the floor is smooth. (a) What maximum horizontal force can be applied without disturbing the equilibrium of the system? (b) Suppose the horizontal force applied is double of that found in part (a). ind the accelerations of the two masses. ig.. Suppose the entire system of the previous question is kept inside an elevator which is coming down with an acceleration a <g. epeat parts (a) and (b). 3. Consider the situation shown in figure. Suppose small electric field E exists in the space in the vertically upward direction and the upper block carries a positive charge Q on its top surface. The friction coefficient between the two blocks is N but the floor is smooth. What maximum horizontal force can be applied without disturbing the equilibrium? 4. block of mass m slips on a rough horizontal table under the action of a horizontal force applied to it. The coefficient of friction between the block and the table is. The table does not move on the floor. ind the total frictional force applied by the floor on the legs of the table: Do you need the friction coefficient between the table and the floor or the mass of the table? 5. ind the acceleration of the block of mass M in the ituation of figure. The coefficient of friction between the two blocks is and that between the bigger block and the ground is µ. ig. 6. block of mass kg is pushed against a rough vertical wall with a force of 40 N, coefficient of static friction being 0.5. nother horizontal force of 5 N, is applied on the block in a direction parallel to the wall. Will the block move? If yes, in which direction? If no, find the frictional force exerted by the wall on the block. 7. person (40 kg) is managing to be at rest between two vertical walls by pressing one wall by his hands and feet and the other wall by his back 3. ssume that the friction coefficient between his body and the walls is 0.8 and that limiting friction acts at all the contacts. (a) Show that the person pushes the two walls with equal force. (b) ind the normal force exerted by either wall on the person. Take g=0m/s. ig.3

21 8. igure 4 shows a small block of mass m kept at the left end of a larger block of mass M and length L. The system can slide on a horizontal road. The system is started towards right with an initial velocity v. The friction coefficient between the road and the bigger block is µ and that between the blocks is. ind the time elapsed before the smaller block separates from the bigger block. ig.4 NSWES. (a) 37 0 (b) 5.0N. (a) tan - (0.3) (b) mg sin(/) 3. s kg 5. g(m+m) 6. / 3 7. s = 0.60, k = mg/ (sin cos) 9. /( sin cos) 0. M mg and (M m) g -. (a) 9/8 kg, 3/9 kg (b) 0.3m/s. = 0.75, = N in the left string and 68 N in the right string m/s,.4 m/s. 6. a = g(sin cos), zero 7. mg/( ) at an angle tan - with the horizontal. 8. m) g/ (+ ) 9. (a) upper block 4 m/s, lower block m/s. (b) both blocks m/s. 0. (a) a = 3 m/s, a = a 3 = 0.4 m/s (b) a = a = a 3 = 5/6 m/s (c) same as (b). (a) mg (b) mg/(m + m) in opposite direction.. (a) mg (b) m(g-a) /(M + m) 3. mg-qe) 4. mg [m 5. M m ]g M m[5 ( )] 6. it will move at an angle of 53 0 with the 5 N force. 7. (b) 50 N 8. 4Ml M mg

66 Chapter 6: FORCE AND MOTION II

66 Chapter 6: FORCE AND MOTION II Chapter 6: FORCE AND MOTION II 1 A brick slides on a horizontal surface Which of the following will increase the magnitude of the frictional force on it? A Putting a second brick on top B Decreasing the

More information

University Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1

University Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1 University Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1 Name: Date: 1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction

More information

For more Study Material and Latest Questions related to IIT-JEE visit

For more Study Material and Latest Questions related to IIT-JEE visit or ore Study Material and Latest Questions related to IIT-JEE visit www. ICTION Introduction If we slide or try to slide a body over a surface, the otion is resisted by a bonding between the body and the

More information

1. A sphere with a radius of 1.7 cm has a volume of: A) m 3 B) m 3 C) m 3 D) 0.11 m 3 E) 21 m 3

1. A sphere with a radius of 1.7 cm has a volume of: A) m 3 B) m 3 C) m 3 D) 0.11 m 3 E) 21 m 3 1. A sphere with a radius of 1.7 cm has a volume of: A) 2.1 10 5 m 3 B) 9.1 10 4 m 3 C) 3.6 10 3 m 3 D) 0.11 m 3 E) 21 m 3 2. A 25-N crate slides down a frictionless incline that is 25 above the horizontal.

More information

AP Physics 1 - Test 05 - Force and Motion

AP Physics 1 - Test 05 - Force and Motion P Physics 1 - Test 05 - Force and Motion Score: 1. brick slides on a horizontal surface. Which of the following will increase the magnitude of the frictional force on it? Putting a second brick on top

More information

PHYS 101 Previous Exam Problems. Force & Motion I

PHYS 101 Previous Exam Problems. Force & Motion I PHYS 101 Previous Exam Problems CHAPTER 5 Force & Motion I Newton s Laws Vertical motion Horizontal motion Mixed forces Contact forces Inclines General problems 1. A 5.0-kg block is lowered with a downward

More information

WS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton ( )

WS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton ( ) AP PHYSICS 1 WS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton (1643-1727) Isaac Newton was the greatest English mathematician of his generation. He laid the foundation for differential

More information

Twentieth SLAPT Physics Contest Southern Illinois University Edwardsville April 30, Mechanics Test

Twentieth SLAPT Physics Contest Southern Illinois University Edwardsville April 30, Mechanics Test Twentieth SLAPT Physics Contest Southern Illinois University Edwardsville April 30, 2005 Mechanics Test Please answer the following questions on the supplied answer sheet. You may write on this test booklet,

More information

CHAPTER 4 NEWTON S LAWS OF MOTION

CHAPTER 4 NEWTON S LAWS OF MOTION 62 CHAPTER 4 NEWTON S LAWS O MOTION CHAPTER 4 NEWTON S LAWS O MOTION 63 Up to now we have described the motion of particles using quantities like displacement, velocity and acceleration. These quantities

More information

Chapter 4 Force and Motion

Chapter 4 Force and Motion Chapter 4 Force and Motion Units of Chapter 4 The Concepts of Force and Net Force Inertia and Newton s First Law of Motion Newton s Second Law of Motion Newton s Third Law of Motion More on Newton s Laws:

More information

Get Solution of These Packages & Learn by Video Tutorials on EXERCISE-1

Get Solution of These Packages & Learn by Video Tutorials on  EXERCISE-1 OBJECTIVE PROBLEMS EXERCISE-. A force of 98 N is require to just start moving a body of mass 00 kg over ice. The coefficient of static friction is : (A) 0.6 0.4 (C) 0. (D) 0.. The maximum static frictional

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) You are standing in a moving bus, facing forward, and you suddenly fall forward as the

More information

Mechanics II. Which of the following relations among the forces W, k, N, and F must be true?

Mechanics II. Which of the following relations among the forces W, k, N, and F must be true? Mechanics II 1. By applying a force F on a block, a person pulls a block along a rough surface at constant velocity v (see Figure below; directions, but not necessarily magnitudes, are indicated). Which

More information

The net force on a moving object is suddenly reduced to zero. As a consequence, the object

The net force on a moving object is suddenly reduced to zero. As a consequence, the object The net force on a moving object is suddenly reduced to zero. As a consequence, the object (A) stops abruptly (B) stops during a short time interval (C) changes direction (D) continues at a constant velocity

More information

CHAPTER 4 TEST REVIEW -- Answer Key

CHAPTER 4 TEST REVIEW -- Answer Key AP PHYSICS Name: Period: Date: DEVIL PHYSICS BADDEST CLASS ON CAMPUS 50 Multiple Choice 45 Single Response 5 Multi-Response Free Response 3 Short Free Response 2 Long Free Response AP EXAM CHAPTER TEST

More information

HSC PHYSICS ONLINE B F BA. repulsion between two negatively charged objects. attraction between a negative charge and a positive charge

HSC PHYSICS ONLINE B F BA. repulsion between two negatively charged objects. attraction between a negative charge and a positive charge HSC PHYSICS ONLINE DYNAMICS TYPES O ORCES Electrostatic force (force mediated by a field - long range: action at a distance) the attractive or repulsion between two stationary charged objects. AB A B BA

More information

PSI AP Physics B Dynamics

PSI AP Physics B Dynamics PSI AP Physics B Dynamics Multiple-Choice questions 1. After firing a cannon ball, the cannon moves in the opposite direction from the ball. This an example of: A. Newton s First Law B. Newton s Second

More information

Chapter 6 Dynamics I: Motion Along a Line

Chapter 6 Dynamics I: Motion Along a Line Chapter 6 Dynamics I: Motion Along a Line Chapter Goal: To learn how to solve linear force-and-motion problems. Slide 6-2 Chapter 6 Preview Slide 6-3 Chapter 6 Preview Slide 6-4 Chapter 6 Preview Slide

More information

4) Vector = and vector = What is vector = +? A) B) C) D) E)

4) Vector = and vector = What is vector = +? A) B) C) D) E) 1) Suppose that an object is moving with constant nonzero acceleration. Which of the following is an accurate statement concerning its motion? A) In equal times its speed changes by equal amounts. B) In

More information

ConcepTest PowerPoints

ConcepTest PowerPoints ConcepTest PowerPoints Chapter 4 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for

More information

PHYS 101 Previous Exam Problems. Kinetic Energy and

PHYS 101 Previous Exam Problems. Kinetic Energy and PHYS 101 Previous Exam Problems CHAPTER 7 Kinetic Energy and Work Kinetic energy Work Work-energy theorem Gravitational work Work of spring forces Power 1. A single force acts on a 5.0-kg object in such

More information

Physics B Newton s Laws AP Review Packet

Physics B Newton s Laws AP Review Packet Force A force is a push or pull on an object. Forces cause an object to accelerate To speed up To slow down To change direction Unit: Newton (SI system) Newton s First Law The Law of Inertia. A body in

More information

The diagram below shows a block on a horizontal frictionless surface. A 100.-newton force acts on the block at an angle of 30. above the horizontal.

The diagram below shows a block on a horizontal frictionless surface. A 100.-newton force acts on the block at an angle of 30. above the horizontal. Name: 1) 2) 3) Two students are pushing a car. What should be the angle of each student's arms with respect to the flat ground to maximize the horizontal component of the force? A) 90 B) 0 C) 30 D) 45

More information

Friction Can Be Rough

Friction Can Be Rough 8.1 Observe and Find a Pattern Friction Can Be Rough Perform the following experiment: Rest a brick on a rough surface. Tie a string around the brick and attach a large spring scale to it. Pull the scale

More information

Physics for Scientists and Engineers. Chapter 6 Dynamics I: Motion Along a Line

Physics for Scientists and Engineers. Chapter 6 Dynamics I: Motion Along a Line Physics for Scientists and Engineers Chapter 6 Dynamics I: Motion Along a Line Spring, 008 Ho Jung Paik Applications of Newton s Law Objects can be modeled as particles Masses of strings or ropes are negligible

More information

Physics 101 Lecture 5 Newton`s Laws

Physics 101 Lecture 5 Newton`s Laws Physics 101 Lecture 5 Newton`s Laws Dr. Ali ÖVGÜN EMU Physics Department The Laws of Motion q Newton s first law q Force q Mass q Newton s second law q Newton s third law qfrictional forces q Examples

More information

AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force).

AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force). AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force). 1981M1. A block of mass m, acted on by a force of magnitude F directed horizontally to the

More information

Exam 1 Solutions. PHY 2048 Spring 2014 Acosta, Rinzler. Note that there are several variations of some problems, indicated by choices in parentheses.

Exam 1 Solutions. PHY 2048 Spring 2014 Acosta, Rinzler. Note that there are several variations of some problems, indicated by choices in parentheses. Exam 1 Solutions Note that there are several variations of some problems, indicated by choices in parentheses. Problem 1 Let vector a! = 4î + 3 ĵ and vector b! = î + 2 ĵ (or b! = î + 4 ĵ ). What is the

More information

Physics 8 Wednesday, October 19, Troublesome questions for HW4 (5 or more people got 0 or 1 points on them): 1, 14, 15, 16, 17, 18, 19. Yikes!

Physics 8 Wednesday, October 19, Troublesome questions for HW4 (5 or more people got 0 or 1 points on them): 1, 14, 15, 16, 17, 18, 19. Yikes! Physics 8 Wednesday, October 19, 2011 Troublesome questions for HW4 (5 or more people got 0 or 1 points on them): 1, 14, 15, 16, 17, 18, 19. Yikes! Troublesome HW4 questions 1. Two objects of inertias

More information

Chapter 2 Dynamics 51

Chapter 2 Dynamics 51 Chapter 2 Dynamics 51 52 AP Physics Multiple Choice Practice Dynamics SECTION A Linear Dynamics 1. A ball of mass m is suspended from two strings of unequal length as shown above. The magnitudes of the

More information

2. If a net horizontal force of 175 N is applied to a bike whose mass is 43 kg what acceleration is produced?

2. If a net horizontal force of 175 N is applied to a bike whose mass is 43 kg what acceleration is produced? Chapter Problems Newton s 2nd Law: Class Work 1. A 0.40 kg toy car moves at constant acceleration of 2.3 m/s 2. Determine the net applied force that is responsible for that acceleration. 2. If a net horizontal

More information

PHYSICS 221, FALL 2009 EXAM #1 SOLUTIONS WEDNESDAY, SEPTEMBER 30, 2009

PHYSICS 221, FALL 2009 EXAM #1 SOLUTIONS WEDNESDAY, SEPTEMBER 30, 2009 PHYSICS 221, FALL 2009 EXAM #1 SOLUTIONS WEDNESDAY, SEPTEMBER 30, 2009 Note: The unit vectors in the +x, +y, and +z directions of a right-handed Cartesian coordinate system are î, ĵ, and ˆk, respectively.

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Diagram 1 A) B - A. B) A - B. C) A + B. D) A B.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Diagram 1 A) B - A. B) A - B. C) A + B. D) A B. Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In the diagram shown, the unknown vector is 1) Diagram 1 A) B - A. B) A - B. C) A + B.

More information

1. A 7.0-kg bowling ball experiences a net force of 5.0 N. What will be its acceleration? a. 35 m/s 2 c. 5.0 m/s 2 b. 7.0 m/s 2 d. 0.

1. A 7.0-kg bowling ball experiences a net force of 5.0 N. What will be its acceleration? a. 35 m/s 2 c. 5.0 m/s 2 b. 7.0 m/s 2 d. 0. Newton's Laws 1. A 7.0-kg bowling ball experiences a net force of 5.0 N. What will be its acceleration? a. 35 m/s 2 c. 5.0 m/s 2 b. 7.0 m/s 2 d. 0.71 m/s 2 2. An astronaut applies a force of 500 N to an

More information

LAHS Physics Semester 1 Final Practice Multiple Choice

LAHS Physics Semester 1 Final Practice Multiple Choice LAHS Physics Semester 1 Final Practice Multiple Choice The following Multiple Choice problems are practice MC for the final. Some or none of these problems may appear on the real exam. Answers are provided

More information

Q2. A book whose mass is 2 kg rests on a table. Find the magnitude of the force exerted by the table on the book.

Q2. A book whose mass is 2 kg rests on a table. Find the magnitude of the force exerted by the table on the book. AP Physics 1- Dynamics Practice Problems FACT: Inertia is the tendency of an object to resist a change in state of motion. A change in state of motion means a change in an object s velocity, therefore

More information

1. The age of the universe is about 14 billion years. Assuming two significant figures, in powers of ten in seconds this corresponds to

1. The age of the universe is about 14 billion years. Assuming two significant figures, in powers of ten in seconds this corresponds to 1. The age of the universe is about 14 billion years. Assuming two significant figures, in powers of ten in seconds this corresponds to A) 9.2 10 12 s B) 8.3 10 14 s C) 1.6 10 16 s D) 4.4 10 17 s E) 2.7

More information

Name: Class: Date: so sliding friction is better so sliding friction is better d. µ k

Name: Class: Date: so sliding friction is better so sliding friction is better d. µ k Name: Class: Date: Exam 2--PHYS 101-F08 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. You put your book on the seat next to you. When the bus stops,

More information

Reading Quiz. Chapter 5. Physics 111, Concordia College

Reading Quiz. Chapter 5. Physics 111, Concordia College Reading Quiz Chapter 5 1. The coefficient of static friction is A. smaller than the coefficient of kinetic friction. B. equal to the coefficient of kinetic friction. C. larger than the coefficient of kinetic

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Common Quiz Mistakes / Practice for Final Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A ball is thrown directly upward and experiences

More information

Chapter 4. Dynamics: Newton s Laws of Motion. That is, describing why objects move

Chapter 4. Dynamics: Newton s Laws of Motion. That is, describing why objects move Chapter 4 Dynamics: Newton s Laws of Motion That is, describing why objects move orces Newton s 1 st Law Newton s 2 nd Law Newton s 3 rd Law Examples of orces: Weight, Normal orce, Tension, riction ree-body

More information

Chapter 4 Newton s Laws

Chapter 4 Newton s Laws Chapter 4 Newton s Laws Isaac Newton 1642-1727 Some inventions and discoveries: 3 laws of motion Universal law of gravity Calculus Ideas on: Sound Light Thermodynamics Reflecting telescope In this chapter,

More information

Review 3: Forces. 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D)

Review 3: Forces. 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D) 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D) 2. A rock is thrown straight up into the air. At the highest point of the rock's path, the magnitude of the net force

More information

Dynamics; Newton s Laws of Motion

Dynamics; Newton s Laws of Motion Dynamics; Newton s Laws of Motion Force A force is any kind of push or pull on an object. An object at rest needs a force to get it moving; a moving object needs a force to change its velocity. The magnitude

More information

Exam 2--PHYS 101--F17

Exam 2--PHYS 101--F17 Name: Exam 2--PHYS 0--F7 Multiple Choice Identify the choice that best completes the statement or answers the question.. A ball is thrown in the air at an angle of 30 to the ground, with an initial speed

More information

Physics. TOPIC : Friction. 1. To avoid slipping while walking on ice, one should take smaller steps because of the

Physics. TOPIC : Friction. 1. To avoid slipping while walking on ice, one should take smaller steps because of the TOPIC : Friction Date : Marks : 0 mks Time : ½ hr. To avoid slipping while walking on ice, one should take smaller steps because of the Friction of ice is large (b Larger normal reaction (c Friction of

More information

1 In the absence of a net force, a moving object will. slow down and eventually stop stop immediately turn right move with constant velocity turn left

1 In the absence of a net force, a moving object will. slow down and eventually stop stop immediately turn right move with constant velocity turn left Slide 1 / 51 1 In the absence of a net force, a moving object will slow down and eventually stop stop immediately turn right move with constant velocity turn left Slide 2 / 51 2 When a cat sleeps on a

More information

y(t) = y 0 t! 1 2 gt 2. With y(t final ) = 0, we can solve this for v 0 : v 0 A ĵ. With A! ĵ =!2 and A! = (2) 2 + (!

y(t) = y 0 t! 1 2 gt 2. With y(t final ) = 0, we can solve this for v 0 : v 0 A ĵ. With A! ĵ =!2 and A! = (2) 2 + (! 1. The angle between the vector! A = 3î! 2 ĵ! 5 ˆk and the positive y axis, in degrees, is closest to: A) 19 B) 71 C) 90 D) 109 E) 161 The dot product between the vector! A = 3î! 2 ĵ! 5 ˆk and the unit

More information

TOPIC B: MOMENTUM EXAMPLES SPRING 2019

TOPIC B: MOMENTUM EXAMPLES SPRING 2019 TOPIC B: MOMENTUM EXAMPLES SPRING 2019 (Take g = 9.81 m s 2 ). Force-Momentum Q1. (Meriam and Kraige) Calculate the vertical acceleration of the 50 cylinder for each of the two cases illustrated. Neglect

More information

Name ID Section. 1. One mile is equal to 1609 m; 1 hour is equal to 3600 s. The highway speed limit of 65 mph is equivalent to the speed of:

Name ID Section. 1. One mile is equal to 1609 m; 1 hour is equal to 3600 s. The highway speed limit of 65 mph is equivalent to the speed of: The exam is closed book and closed notes. There are 30 multiple choice questions. Make sure you put your name, section, and ID number on the SCANTRON form. The answers for the multiple choice Questions

More information

Chapter Four Holt Physics. Forces and the Laws of Motion

Chapter Four Holt Physics. Forces and the Laws of Motion Chapter Four Holt Physics Forces and the Laws of Motion Physics Force and the study of dynamics 1.Forces - a. Force - a push or a pull. It can change the motion of an object; start or stop movement; and,

More information

Old Exam. Question Chapter 7 072

Old Exam. Question Chapter 7 072 Old Exam. Question Chapter 7 072 Q1.Fig 1 shows a simple pendulum, consisting of a ball of mass M = 0.50 kg, attached to one end of a massless string of length L = 1.5 m. The other end is fixed. If the

More information

Online homework #6 due on Tue March 24

Online homework #6 due on Tue March 24 Online homework #6 due on Tue March 24 Problem 5.22 Part A: give your answer with only 2 significant digits (i.e. round answer and drop less significant digits) 51 Equilibrium Question 52 1 Using Newton

More information

Practice Honors Physics Test: Newtons Laws

Practice Honors Physics Test: Newtons Laws Name: Class: Date: Practice Honors Physics Test: Newtons Laws Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Acceleration is defined as the CHANGE in

More information

3. The diagram shows two bowling balls, A and B, each having a mass of 7.00 kilograms, placed 2.00 meters apart.

3. The diagram shows two bowling balls, A and B, each having a mass of 7.00 kilograms, placed 2.00 meters apart. 1. Which statement describes the gravitational force and the electrostatic force between two charged particles? A) The gravitational force may be either attractive or repulsive, whereas the electrostatic

More information

2. Kinetic friction - The force that acts against an object s motion. - Occurs once static friction has been overcome and object is moving

2. Kinetic friction - The force that acts against an object s motion. - Occurs once static friction has been overcome and object is moving Section 2.14: Friction Friction is needed to move. Without friction, a car would sit in one spot spinning its tires, and a person would not be able to step forward. However, the motion of an object along

More information

RELEASED. Go to next page. 2. The graph shows the acceleration of a car over time.

RELEASED. Go to next page. 2. The graph shows the acceleration of a car over time. 1. n object is launched across a room. How can a student determine the average horizontal velocity of the object using a meter stick and a calculator? The student can calculate the object s initial potential

More information

Chapter 6. Force and Motion II

Chapter 6. Force and Motion II Chapter 6 Force and Motion II 6 Force and Motion II 2 Announcement: Sample Answer Key 3 4 6-2 Friction Force Question: If the friction were absent, what would happen? Answer: You could not stop without

More information

Q16.: A 5.0 kg block is lowered with a downward acceleration of 2.8 m/s 2 by means of a rope. The force of the block on the rope is:(35 N, down)

Q16.: A 5.0 kg block is lowered with a downward acceleration of 2.8 m/s 2 by means of a rope. The force of the block on the rope is:(35 N, down) Old Exam Question Ch. 5 T072 Q13.Two blocks of mass m 1 = 24.0 kg and m 2, respectively, are connected by a light string that passes over a massless pulley as shown in Fig. 2. If the tension in the string

More information

An object moves back and forth, as shown in the position-time graph. At which points is the velocity positive?

An object moves back and forth, as shown in the position-time graph. At which points is the velocity positive? 1 The slope of the tangent on a position-time graph equals the instantaneous velocity 2 The area under the curve on a velocity-time graph equals the: displacement from the original position to its position

More information

Dynamics Multiple Choice Homework

Dynamics Multiple Choice Homework Dynamics Multiple Choice Homework PSI Physics Name 1. In the absence of a net force, a moving object will A. slow down and eventually stop B. stop immediately C. turn right D. move with constant velocity

More information

Phys , Fall04,Term 1 Exercise Problems

Phys , Fall04,Term 1 Exercise Problems Page 1 1. The number of significant figures in the number 0.00593 is a. 5 b. 2 c. 3 d.6 2. The product of 10-4 and 105 is a. 1 b. 10 c. 0.1 d.100 3. The length of a car is given as 4.57 m. The percent

More information

AP Physics 1: MIDTERM REVIEW OVER UNITS 2-4: KINEMATICS, DYNAMICS, FORCE & MOTION, WORK & POWER

AP Physics 1: MIDTERM REVIEW OVER UNITS 2-4: KINEMATICS, DYNAMICS, FORCE & MOTION, WORK & POWER MIDTERM REVIEW AP Physics 1 McNutt Name: Date: Period: AP Physics 1: MIDTERM REVIEW OVER UNITS 2-4: KINEMATICS, DYNAMICS, FORCE & MOTION, WORK & POWER 1.) A car starts from rest and uniformly accelerates

More information

AP Physics 1 Multiple Choice Questions - Chapter 4

AP Physics 1 Multiple Choice Questions - Chapter 4 1 Which of ewton's Three Laws of Motion is best expressed by the equation F=ma? a ewton's First Law b ewton's Second Law c ewton's Third Law d one of the above 4.1 2 A person is running on a track. Which

More information

Sample Physics Placement Exam

Sample Physics Placement Exam Sample Physics 130-1 Placement Exam A. Multiple Choice Questions: 1. A cable is used to take construction equipment from the ground to the top of a tall building. During the trip up, when (if ever) is

More information

An Accelerating Hockey Puck

An Accelerating Hockey Puck Example 5.1 An Accelerating Hockey Puck A hockey puck having a mass of 0.30 kg slides on the frictionless, horizontal surface of an ice rink. Two hockey sticks strike the puck simultaneously, exerting

More information

Chapter 4. Table of Contents. Section 1 Changes in Motion. Section 2 Newton's First Law. Section 3 Newton's Second and Third Laws

Chapter 4. Table of Contents. Section 1 Changes in Motion. Section 2 Newton's First Law. Section 3 Newton's Second and Third Laws Forces and the Laws of Motion Table of Contents Section 1 Changes in Motion Section 2 Newton's First Law Section 3 Newton's Second and Third Laws Section 4 Everyday Forces Section 1 Changes in Motion Objectives

More information

Phys101-T121-First Major Exam Zero Version, choice A is the correct answer

Phys101-T121-First Major Exam Zero Version, choice A is the correct answer Phys101-T121-First Major Exam Zero Version, choice A is the correct answer Q1. Find the mass of a solid cylinder of copper with a radius of 5.00 cm and a height of 10.0 inches if the density of copper

More information

PH201 Chapter 5 Solutions

PH201 Chapter 5 Solutions PH201 Chapter 5 Solutions 5.4. Set Up: For each object use coordinates where +y is upward. Each object has Call the objects 1 and 2, with and Solve: (a) The free-body diagrams for each object are shown

More information

PRACTICE TEST for Midterm Exam

PRACTICE TEST for Midterm Exam South Pasadena AP Physics PRACTICE TEST for Midterm Exam FORMULAS Name Period Date / / d = vt d = v o t + ½ at 2 d = v o + v 2 t v = v o + at v 2 = v 2 o + 2ad v = v x 2 + v y 2 = tan 1 v y v v x = v cos

More information

Equilibrium & Elasticity

Equilibrium & Elasticity PHYS 101 Previous Exam Problems CHAPTER 12 Equilibrium & Elasticity Static equilibrium Elasticity 1. A uniform steel bar of length 3.0 m and weight 20 N rests on two supports (A and B) at its ends. A block

More information

Physics 207 Lecture 7. Lecture 7

Physics 207 Lecture 7. Lecture 7 Lecture 7 "Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled

More information

AP Physics First Nine Weeks Review

AP Physics First Nine Weeks Review AP Physics First Nine Weeks Review 1. If F1 is the magnitude of the force exerted by the Earth on a satellite in orbit about the Earth and F2 is the magnitude of the force exerted by the satellite on the

More information

The Laws of Motion. Newton s first law Force Mass Newton s second law Gravitational Force Newton s third law Examples

The Laws of Motion. Newton s first law Force Mass Newton s second law Gravitational Force Newton s third law Examples The Laws of Motion Newton s first law Force Mass Newton s second law Gravitational Force Newton s third law Examples Gravitational Force Gravitational force is a vector Expressed by Newton s Law of Universal

More information

Lecture 6. Applying Newton s Laws Free body diagrams Friction

Lecture 6. Applying Newton s Laws Free body diagrams Friction Lecture 6 Applying Newton s Laws Free body diagrams Friction ACT: Bowling on the Moon An astronaut on Earth kicks a bowling ball horizontally and hurts his foot. A year later, the same astronaut kicks

More information

Physics 8 Monday, October 12, 2015

Physics 8 Monday, October 12, 2015 Physics 8 Monday, October 12, 2015 HW5 will be due Friday. (HW5 is just Ch9 and Ch10 problems.) You re reading Chapter 12 ( torque ) this week, even though in class we re just finishing Ch10 / starting

More information

Show all workings for questions that involve calculations. No marks will be given for correct answers that are not supported by calculations.

Show all workings for questions that involve calculations. No marks will be given for correct answers that are not supported by calculations. Assignment 8 Unit 2 Newton s Laws (Outcomes 325-5, 325-8) Name: Multiple Choice: Show all workings for questions that involve calculations. No marks will be given for correct answers that are not supported

More information

Physics 2A Chapter 4: Forces and Newton s Laws of Motion

Physics 2A Chapter 4: Forces and Newton s Laws of Motion Physics 2A Chapter 4: Forces and Newton s Laws of Motion There is nothing either good or bad, but thinking makes it so. William Shakespeare It s not what happens to you that determines how far you will

More information

Physics Midterm Review KEY

Physics Midterm Review KEY Name: Date: 1. Which quantities are scalar? A. speed and work B. velocity and force C. distance and acceleration D. momentum and power 2. A 160.-kilogram space vehicle is traveling along a straight line

More information

Chapters 5-6. Dynamics: Forces and Newton s Laws of Motion. Applications

Chapters 5-6. Dynamics: Forces and Newton s Laws of Motion. Applications Chapters 5-6 Dynamics: orces and Newton s Laws of Motion. Applications That is, describing why objects move orces Newton s 1 st Law Newton s 2 nd Law Newton s 3 rd Law Examples of orces: Weight, Normal,

More information

PYP 001 FIRST MAJOR EXAM CODE: TERM: 151 SATURDAY, OCTOBER 17, 2015 PAGE: 1

PYP 001 FIRST MAJOR EXAM CODE: TERM: 151 SATURDAY, OCTOBER 17, 2015 PAGE: 1 TERM: 151 SATURDAY, OCTOBER 17, 2015 PAGE: 1 *Read the following (20) questions and choose the right answer: 1 The figure below represents the speed-time graph for the motion of a vehicle during a 7.0-minute

More information

End-of-Chapter Exercises

End-of-Chapter Exercises End-of-Chapter Exercises For all these exercises, assume that all strings are massless and all pulleys are both massless and frictionless. We will improve our model and learn how to account for the mass

More information

B C = B 2 + C 2 2BC cosθ = (5.6)(4.8)cos79 = ) The components of vectors B and C are given as follows: B x. = 6.

B C = B 2 + C 2 2BC cosθ = (5.6)(4.8)cos79 = ) The components of vectors B and C are given as follows: B x. = 6. 1) The components of vectors B and C are given as follows: B x = 6.1 C x = 9.8 B y = 5.8 C y = +4.6 The angle between vectors B and C, in degrees, is closest to: A) 162 B) 111 C) 69 D) 18 E) 80 B C = (

More information

C) D) 2. The diagram below shows a worker using a rope to pull a cart.

C) D) 2. The diagram below shows a worker using a rope to pull a cart. 1. Which graph best represents the relationship between the acceleration of an object falling freely near the surface of Earth and the time that it falls? 2. The diagram below shows a worker using a rope

More information

Chapter 4. Forces and Newton s Laws of Motion. F=ma; gravity

Chapter 4. Forces and Newton s Laws of Motion. F=ma; gravity Chapter 4 Forces and Newton s Laws of Motion F=ma; gravity 0) Background Galileo inertia (horizontal motion) constant acceleration (vertical motion) Descartes & Huygens Conservation of momentum: mass x

More information

PHYSICS. Chapter 5 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc.

PHYSICS. Chapter 5 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc. PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 5 Lecture RANDALL D. KNIGHT Chapter 5 Force and Motion IN THIS CHAPTER, you will learn about the connection between force and motion.

More information

8. An elevator without a ceiling is ascending with a constant speed of 6 m/s. A boy on the elevator throws a ball directly upward, from a height of 2.

8. An elevator without a ceiling is ascending with a constant speed of 6 m/s. A boy on the elevator throws a ball directly upward, from a height of 2. O. P. JINDAL SCHOOL, RAIGARH (CG) 496 001, INDIA Phone: 07762-227042, 227293, (Extn. 227001-49801, 02, 04, 06, 09); Fax: 07762-262613; website: www.opjsrgh.in; e-mail: opjsraigarh@jspl.com CLASS: XI- PHYSICS

More information

AP Physics I Summer Work

AP Physics I Summer Work AP Physics I Summer Work 2018 (20 points) Please complete the following set of questions and word problems. Answers will be reviewed in depth during the first week of class followed by an assessment based

More information

UIC PHYSICS 105 Fall st Midterm Exam

UIC PHYSICS 105 Fall st Midterm Exam UIC: Physics 105 1st Midterm Exam Fall 2014 Thursday, October 2 # LAST Name (print) FIRST Name (print) Signature: UIN #: Giving or receiving aid in any examination is cause for dismissal from the University.

More information

The Concept of Force Newton s First Law and Inertial Frames Mass Newton s Second Law The Gravitational Force and Weight Newton s Third Law Analysis

The Concept of Force Newton s First Law and Inertial Frames Mass Newton s Second Law The Gravitational Force and Weight Newton s Third Law Analysis The Laws of Motion The Concept of Force Newton s First Law and Inertial Frames Mass Newton s Second Law The Gravitational Force and Weight Newton s Third Law Analysis Models using Newton s Second Law Forces

More information

+F N = -F g. F g = m٠a g

+F N = -F g. F g = m٠a g Force Normal = F N Force Normal (or the Normal Force, abbreviated F N ) = F N = The contact force exerted by a surface on an object. The word Normal means perpendicular to Therefore, the Normal Force is

More information

(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m

(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m PSI AP Physics C Work and Energy (Algebra Based) Multiple Choice Questions (use g = 10 m/s 2 ) 1. A student throws a ball upwards from the ground level where gravitational potential energy is zero. At

More information

CHAPTER 2. Knowledge. For each question, select the best answer from the four alternatives.

CHAPTER 2. Knowledge. For each question, select the best answer from the four alternatives. CHAPTER 2 Review K/U Knowledge/Understanding T/I Thinking/Investigation C Communication A Application Knowledge For each question, select the best answer from the four alternatives. 1. When a body is at

More information

Forces. Isaac Newton stated 3 laws that deal with forces and describe motion. Backbone of Physics

Forces. Isaac Newton stated 3 laws that deal with forces and describe motion. Backbone of Physics FORCES Forces Isaac Newton stated 3 laws that deal with forces and describe motion. Backbone of Physics Inertia Tendency of an object to remain in the same state of motion. Resists a change in motion.

More information

Q1. Which of the following is the correct combination of dimensions for energy?

Q1. Which of the following is the correct combination of dimensions for energy? Tuesday, June 15, 2010 Page: 1 Q1. Which of the following is the correct combination of dimensions for energy? A) ML 2 /T 2 B) LT 2 /M C) MLT D) M 2 L 3 T E) ML/T 2 Q2. Two cars are initially 150 kilometers

More information

Newton s Laws.

Newton s Laws. Newton s Laws http://mathsforeurope.digibel.be/images Forces and Equilibrium If the net force on a body is zero, it is in equilibrium. dynamic equilibrium: moving relative to us static equilibrium: appears

More information

HATZIC SECONDARY SCHOOL

HATZIC SECONDARY SCHOOL HATZIC SECONDARY SCHOOL PROVINCIAL EXAMINATION ASSIGNMENT VECTOR DYNAMICS MULTIPLE CHOICE / 45 OPEN ENDED / 75 TOTAL / 120 NAME: 1. Unless acted on by an external net force, an object will stay at rest

More information

Tue Sept 15. Dynamics - Newton s Laws of Motion. Forces: Identifying Forces Free-body diagram Affect on Motion

Tue Sept 15. Dynamics - Newton s Laws of Motion. Forces: Identifying Forces Free-body diagram Affect on Motion Tue Sept 15 Assignment 4 Friday Pre-class Thursday Lab - Print, do pre-lab Closed toed shoes Exam Monday Oct 5 7:15-9:15 PM email me if class conflict or extended time Dynamics - Newton s Laws of Motion

More information

Consider the case of a 100 N. mass on a horizontal surface as shown below:

Consider the case of a 100 N. mass on a horizontal surface as shown below: 1.9.1 Introduction The study of friction is called: The force of friction is defined as: The force of friction acting between two surfaces has three properties: i) ii) iii) Consider the case of a 100 N.

More information

A) more mass and more inertia C) the same as the magnitude of the rock's weight C) a man standing still on a bathroom scale

A) more mass and more inertia C) the same as the magnitude of the rock's weight C) a man standing still on a bathroom scale 1. A 15-kilogram cart is at rest on a horizontal surface. A 5-kilogram box is placed in the cart. Compared to the mass and inertia of the cart, the cart-box system has A) more mass and more inertia B)

More information