Lecture 6. Applying Newton s Laws Free body diagrams Friction

Size: px
Start display at page:

Download "Lecture 6. Applying Newton s Laws Free body diagrams Friction"

Transcription

1 Lecture 6 Applying Newton s Laws Free body diagrams Friction

2 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 a bowling ball on the moon with the same force. His foot hurts: A. More B. Less C. The same

3 EXAMPLE: Box hanging from the ceiling. A box of mass m hangs from the ceiling. Determine the tension on the string.

4 EXAMPLE: Box hanging from the ceiling. A box of mass m hangs from the ceiling. Determine the tension on the string. T box,string T W = ma = 0 T = W = mg W box,earth

5 ACT: Fishing A fish is being yanked upward out of the water with a line that can stand a maximum tension of 180 N. The string snaps when the acceleration of the fish is 8 m/s 2. What is the mass of the fish? A. 8 kg snap! B. 10 kg C. 18 kg a = 8 m/s 2

6 A little more difficult: two boxes. String 1 String 1 T s1,ceiling T s1,u String 2 String 2 T s2,u T s2,l

7 A little more difficult: two boxes. String 1 Upper box: String 1 T s1,ceiling T 1 T 2 W U = m U a = 0 T U,s2 String 2 T U,s1 W U,E T s1,u String 2 T 1 = W U + T 2 = W U + W L = (m U + m L ) g Lower box: T L,s2 T s2,u T 2 W L = m L a = 0 T 2 = W L = m L g W L,E T s2,l

8 What if the boxes hang from the ceiling of an accelerated elevator? String 1 T U,s1 T U,s2 String 2 W U,E a T L,s2 W L,E

9 What if the boxes hang from the ceiling of an accelerated elevator? String 1 Upper box: T U,s1 T 1 T 2 W U = m U a T U,s2 T L,s2 String 2 W U,E a Lower box: T 2 W L = m L a Simply keep the a in the equations! W L,E

10 ACT: Sharing the weight. In both of the cases depicted below, a 2-kg weight is supported by two strings. In which case are the students holding the strings exerting a force of greater magnitude? 1. Case A 2. Case B A 3. Both the same B

11 Cable example Find the tension in the cables. θ θ m

12 Cable example Find the tension in the cables. θ T 1 m T 2 θ y mg x x : T 1 cosθ T 2 cosθ = 0 T 1 = T 2 T y : T 1 sinθ + T 2 sinθ mg = 0 2T sinθ = mg T mg 2sin Small θ, large T It is impossible for a real cable (m > 0) to be completely horizontal (it would require infinite tension, and then the cable snaps).

13 N by pivot Atwood s Machine Reasonable direction of motion: Take + in this direction T T 2mg T 2ma T mg ma T = m (a + g) (Mg = 0) T T m 2m mg 2mg 2 mg m( a g ) 2ma g 4 a ; T mg 3 3 mg T 2mg Note: Net force is in the right direction for each box!

14 ACT: A weight vs. a hand In figure 1, a 10-kg mass hangs from a string and pulls on a box of mass m. In figure 2, a hand provides a constant downward force of 98.1 N and pulls on another box of mass m. The pulleys and strings are all ideal and massless. Where does the box experience a larger acceleration? m m 10 kg Fig. 1 T 2 = 98.1 N Fig. 2 A. In figure 1. B. In figure 2. C. It s the same in both.

15 A. Mg B. Mg/2 Example: Pulley How much force does the worker have to exert in order to support the mass M at constant height h off the ground? C. Mgh D. Mg/h E. Mg/(2h) h M

16 A. Mg B. Mg/2 Example: Pulley How much force does the worker have to exert in order to support the mass M at constant height h off the ground? C. Mgh D. Mg/h E. Mg/(2h) h M

17 orange pulley: T 2T green pulley: T 2T mass M: T Mg 0 3 T 1 T 2 T 1 T T Mg 2 T T 1 T 3 T 1 T 3 T 1 Mg 2 Mg

18 Optional: Example: Pulleys A sack of weight w hangs motionless from a system of pulleys. All ropes and pulleys are massless. What is the magnitude of the force is exerted by the worker?

19 T 1 T T T 3 T T T T T 4 T 2 T 4 T T w T 2 T 1 = T 2 = T 3 = T 4 = 2T w = 4T T 4 w T 2 + T 4 = w T?

20 In practice, just count the number of ropes providing support to hanging pulleys. T 4 w DEMO: Pulleys

21 Kinetic and Static Friction A friction is a force that resists relative motion of two bodies in contact with each other. The origin of friction is microscopic irregularities of a surface. Force of friction is always parallel to the surface. Static friction exits between two objects which have a contact and do not move relative one another. Kinetic friction occurs between two objects which have a contact and are moving relative one another.

22 Static Friction Static friction on an object by a surface is opposite in direction to tendancy of motion of the object relative to the surface. The kinetic friction force on an object by can take any value between zero and a maximu value, f s,max. f s μ s N Examples: Allows us to walk, accelerates and decelerates cars (when no skidding), A box on an incline not sliding, etc.

23 Friction f k = μ k N f s μ s N For any two material: μ k μ s Materials Kinetic, μ k Static, μ s Rubber on concrete (dry) Steel on Steel Copper on Steel Rubber on Concete (wet) Steel on ice Teflon on Teflon

24 Example: Trying to move a trunk friction μ s N μ k N F by you

25 Example: Trying to move a trunk friction μ s N F by you f S by floor μ k N F by you

26 Example: Trying to move a trunk friction μ s N F by you f S by floor μ k N F by you

27 Example: Trying to move a trunk friction μ s N F by you f S by floor μ k N F by you

28 Example: Trying to move a trunk friction μ s N F by you f S by floor μ k N F by you

29 Example: Trying to move a trunk friction μ s N F by you f k by floor μ k N F by you

30 Example: Trying to move a trunk friction μ s N F by you f k by floor μ k N F by you Static friction Kinetic friction

31 Car The static friction between the tire and the road pushes the car forward when speeding up without slipping. Rotation of the tire DEMO: Tire Static friction on tire by road

32 Car Speeding up too much so tires slip, then kinetic friction pushes the car forward. Rotation of the tire kinetic friction on tire by road

33 EXAMPLE: Box on incline with friction A box slides down an incline with angle θ = 45. The coefficient of kinetic friction between the box and the plane is μ k = 0.2. Find the acceleration of the box. θ

34 x: W x f k = ma Y: N W y = 0 mg sinθ μ k N = ma N mg cosθ = 0 mg sinθ μ k mg cosθ = ma y a = g (sinθ μ k cosθ ) = 5.5 m/s 2 N B,I x f k B,I W x W y θ W B,E θ

35 Example: Incline and pulley Find the acceleration of the boxes when the system below is released. Friction is negligible. 2m m 35

36 Example: Incline and pulley Find the acceleration of the boxes when the system below is released. Friction is negligible. 2m Same acceleration for both (they move together) m 35

37 1. Draw free body diagram for both boxes. 2. Select axes 3. Write Newton s 2 nd law T N y T mg ma { 2mg sinθ T =2ma N 2mg cosθ = 0 x T m mg 2m 2mg 35 x

38 4. Solve equations { 2 mg sin θ T =2 ma T mg =ma 2 mg sinθ mg = 3 ma g (2 sinθ 1) = 3 a a g 3 2sin 1 = g 3 (2 sin 35 1) = g = 0.48 m/s2 a If θ <30, a < 0 x m 2m θ y x

39 EXAMPLE: Incline and pulley, with friction Same system, but μ s = 0.2 and μ k = 0.1 What happens when the system is released? 2m m 35

40 Does the system move at all? Net force, along the direction of motion, without friction: F net = 2 mg sin 35 mg =0.15 mg Maximum static friction force: f S,MAX S N = μ s 2 mg cos mg This equals to the needed friction that keeps the box from sliding (setting a = 0 in the previous example)! Motion without friction f S f s < f s,max N y It does not move! T 2m x T m 2mg 35 x μ S = 0.2 μ k = 0.1 mg

41 ACT: Magnitude of friction What is the magnitude of the static force in the system we just studied? A mg B mg C mg f S N F f net, no friction S,max T 2m T m 2mg 35 mg 0.33mg 0.15mg

42 ACT: Book against wall When you push a book against a wall, the static friction between the wall and the book can prevent it from falling. If you press harder, the friction force will be: A. Larger than before B. The same C. Smaller than before.

43 Example: Box on truck A box with mass m = 50 kg sits on the back of a truck. The coefficients of friction between the box and the truck are μ k = 0.2 and μ s = 0.4. What is the maximum acceleration that the truck can have without the box slipping? A. 2.0 m/s 2 B. 3.1 m/s 2 C. 3.9 m/s 2 D. 4.9 m/s 2 E. 9.8 m/s 2 a m

44 a f s B,T N B,T Direction of motion relative to the truck in the absence of friction Not slipping: static W B,E f s = m B a N-W = 0 F s,max = m B a MAX a max f S,MAX m B SN m B SmB g m B S g 0.4g 3.9 m/s Answer C 2

45 EXAMPLE: Is N = mg always? A box of mass m = 1.5 kg is being pulled by a string with tension T = 45 N. The string makes an angle θ = 15 with the horizontal. What is the normal force on the box by the floor? θ T m

46 EXAMPLE: Is N = mg always? A box of mass m = 1.5 kg is being pulled by a string with tension T = 45 N. The string makes an angle θ = 15 with the horizontal. What is the normal force on the box by the floor? N T T θ T y = T sinθ θ m T x = T cosθ FBD mg Y direction: F y = m a y N +T sin θ mg = 0 N = mg T sin θ ( <mg) =(1.5 kg)(9.80 m/s 2 ) (45 N sin 15 ) = 3.05 N mg = (1.5 kg)(9.80 m/s 2 ) = 14.7 N

47 EXAMPLE: Box on another box A box of mass m 1 = 1.5 kg is being pulled by a horizontal string with tension T = 45 N. It slides with friction (μ k = 0.50, μ s = 0.70) on top of a second box of mass m 2 = 3.0 kg, which in turn sits on a frictionless floor. Find the acceleration of box 2. T a 1 m 1 μ s = 0.5 a 2? m 2 frictionless

48 T m 1 N f k m 2 f k m 1 g For box 2: f K = μ K N = m 2 a 2 From box 1, we know that N - m 1 g = 0 a 2 N m 1.5 kg k k g 0.50 (9.8 m/s ) 2.5 m/s m2 m2 3.0 kg

49 The magnitude of the tension did not play any role! EXCEPT that the tension just needs to be large enough so the boxes cannot move together. If they moved together, the acceleration of both blocks would be: T 45 N 10 m/s 2 a m 1 m m 4.5 kg T 1 2 The static friction would be the only horizontal force on m 2 : F on m2 = f s = m 2 a = (3.0 kg)(10 m/s 2 ) = 30 N But static friction has a maximum value: f s,max =μ s N = μ s m 1 g ( where N =m 1 g ) m 2 f s = 0.7 (1.5 kg) (9.8 m/s 2 ) = 10.3 N f s N m 1 g f s > f s,max!!!! Since f s required for locking blocks together is larger than the Maximum value friction can provide, Blocks will not stick together in motion for the given value of T

50 ACT: Force and acceleration (2) Two blocks of masses m and 2m are pushed together along a horizontal, frictionless surface by a force F. The magnitude of the net force on block B is: A. 1/3 F B. 2/3 F C. F F m A 2m B

51 Newton s Third Law For every force, or action there is an equal but opposite force, or reaction. Forces ALWAYS happen in pairs. F F AB BA

52 Newton s third law: Action and Reaction Example: Gravitation. You attract the Earth! F g you,earth F g you,earth = F g Earth, you F g Earth, you But the acceleration that this produces on the Earth is a 2 your weight (70 kg)(10 m/s ) m/s, 24 M 6 10 kg Earth (nothing to be too proud of )

53 Leaning on a wall N wall, person N person,wall

54 Rocket Ship Newton s third law implies that if a rocket accelerates forwards, something must be pushed backwards. In outer space, there isn t much else around besides its own fuel. rocket f

55 A Book on a Table Normal on book by table Are forces shown Newton pair?

56 Normal on table by book Normal on book by table

57 Book on Table The full story W TE W ET N BT W BE N TE N TB W EB N ET Action-Reaction Pairs Normal force between book and table N BT = N TB Gravitational force between book and earth W BE = W EB Normal force between table and earth N TE = N ET Gravitational force between table and earth W TE = W ET The book does not accelerate W BE +N BT =0 The table does not accelerate W TE +N TB +N TE =0 Does the earth accelerate?

58 Free Body Diagram It is a diagram with all the forces acting on one object. one all N BT N TE W BE W TE N TB You should always draw a free-body diagram before attempting an application of Newton s second law!!! * * This instructor declines all responsibility for a failed question and will disregard any whining if a free-body diagram has not been drawn.

59 Example: Apparent weight John has a mass of 100 kg and is standing on a scale in an elevator which is accelerating upwards from rest at 2 m/s². What will the scale read? What does a scale measure? The magnitude of the normal force on the scale by John, N JS = N SJ N on John, by scale a (not part of John s free body diagram) W on John, by Earth Newton s 2nd law on John: JS JE J N W m a N on scale, by John John moves rigidly with the elevator

60 John has a mass of 100 kg and standing on a scale in an elevator which is accelerating upwards from rest at 2 m/s². What will the scale read? N W m a JS JE JS J J J N m g m a N m g m a JS J J J m g a 2 2 (100 kg)(9.8 m/s 2.0 m/s ) 1180 N N on John, by scale a W on John, by Earth If the scale is in kg, it will read: N 1180 N kg JS g 9.8 m/s Check: When the elevator is at rest (a = 0), the scale must read the correct weight, 100 kg (980N). Note: In Physics or at least in this course-, the word weight refers to mg, not to what a scale reads.

61 ACT: Force and acceleration (3) Two blocks of masses m and 2m are pushed together along a horizontal, frictionless surface by a force F. The magnitude of the force on block A by block B is: A. 1/3 F F m A 2m B B. 2/3 F C. F

62 ACT: Force and acceleration (3) Two blocks of masses m and 2m are pushed together along a horizontal, frictionless surface by a force F. The magnitude of the force on block A by block B is: A. 1/3 F F m A 2m B B. 2/3 F C. F

63 Example: Box on an incline A hand keeps a 35-kg box from sliding down a frictionless incline. The plane of the incline makes an angle θ = 25 with the horizontal. What is the magnitude of the force exerted by hand? A. 35 N B. 311 N C. 343 N D. 145 N E. 100 N θ

64 Example: Box on an incline A hand keeps a 35-kg box from sliding down a frictionless incline. The plane of the incline makes an angle θ = 25 with the horizontal. What is the magnitude of the force exerted by hand? Draw the free-body diagram A. 35 N B. 311 N C. 343 N D. 145 N Choose axes (draw them!) Use Newton s 2 nd law in the x and y-directions. E. 100 N θ

65 A hand keeps a 35-kg box from sliding down a frictionless incline. The plane of the incline makes an angle θ = 25 with the horizontal. What is the magnitude of the force exerted by hand? W x F = m a x = 0 N - W y = m a y = 0 y F B,hand N B,I F = W x = mg sinθ N = W y = mg cosθ F = mg sinθ = (35 kg)(9.8 m/s 2 )sin(25 ) = 145 N (Answer D) x W x = mg sinθ mg cosθ = W y θ θ W B,E

LECTURE 12 FRICTION, STRINGS & SPRINGS. Instructor: Kazumi Tolich

LECTURE 12 FRICTION, STRINGS & SPRINGS. Instructor: Kazumi Tolich LECTURE 12 FRICTION, STRINGS & SPRINGS Instructor: Kazumi Tolich Lecture 12 2! Reading chapter 6-1 to 6-4! Friction " Static friction " Kinetic friction! Strings! Pulleys! Springs Origin of friction 3!!

More information

Chapter 4. Forces and Newton s Laws of Motion. continued

Chapter 4. Forces and Newton s Laws of Motion. continued Chapter 4 Forces and Newton s Laws of Motion continued 4.9 Static and Kinetic Frictional Forces When an object is in contact with a surface forces can act on the objects. The component of this force acting

More information

Lecture 5. Dynamics. Forces: Newton s First and Second

Lecture 5. Dynamics. Forces: Newton s First and Second Lecture 5 Dynamics. Forces: Newton s First and Second What is a force? It s a pull or a push: F F Force is a quantitative description of the interaction between two physical bodies that causes them to

More information

Webreview practice test. Forces (again)

Webreview practice test. Forces (again) Please do not write on test. ID A Webreview 4.3 - practice test. Forces (again) Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A 5.0-kg mass is suspended

More information

Phys 1401: General Physics I

Phys 1401: General Physics I 1. (0 Points) What course is this? a. PHYS 1401 b. PHYS 1402 c. PHYS 2425 d. PHYS 2426 2. (0 Points) Which exam is this? a. Exam 1 b. Exam 2 c. Final Exam 3. (0 Points) What version of the exam is this?

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 1401: General Physics I

Phys 1401: General Physics I 1. (0 Points) What course is this? a. PHYS 1401 b. PHYS 1402 c. PHYS 2425 d. PHYS 2426 2. (0 Points) Which exam is this? a. Exam 1 b. Exam 2 c. Final Exam 3. (0 Points) What version of the exam is this?

More information

9/20/11. Physics 101 Tuesday 9/20/11 Class 8" Chapter " Weight and Normal forces" Frictional Forces"

9/20/11. Physics 101 Tuesday 9/20/11 Class 8 Chapter  Weight and Normal forces Frictional Forces Reading Quiz Physics 101 Tuesday 9/20/11 Class 8" Chapter 5.6 6.1" Weight and Normal forces" Frictional Forces" The force due to kinetic friction is usually larger than the force due to static friction.

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

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

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

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

Physics 100: Lecture 4b Chapter 4

Physics 100: Lecture 4b Chapter 4 Physics 100: Lecture 4b Chapter 4 Today s Agenda More discussion of dynamics Recap The Free Body Diagram The tools we have for making & solving problems:» Ropes & Pulleys (tension)» Hooke s Law (springs)

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

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

Newton s 3 Laws of Motion

Newton s 3 Laws of Motion Newton s 3 Laws of Motion 1. If F = 0 No change in motion 2. = ma Change in motion Fnet 3. F = F 1 on 2 2 on 1 Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of

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

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

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

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

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

Section /07/2013. PHY131H1F University of Toronto Class 12 Preclass Video by Jason Harlow. Based on Knight 3 rd edition Ch. 7, pgs.

Section /07/2013. PHY131H1F University of Toronto Class 12 Preclass Video by Jason Harlow. Based on Knight 3 rd edition Ch. 7, pgs. PHY131H1F University of Toronto Class 12 Preclass Video by Jason Harlow Section 7.1 Based on Knight 3 rd edition Ch. 7, pgs. 167-184 When a hammer hits a nail, it exerts a forward force on the nail At

More information

Chapter 7 Newton s Third Law

Chapter 7 Newton s Third Law Chapter 7 Newton s Third Law Chapter Goal: To use Newton s third law to understand interacting objects. Slide 7-2 Chapter 7 Preview Slide 7-3 Chapter 7 Preview Slide 7-4 Chapter 7 Preview Slide 7-6 Chapter

More information

Newton s 3 rd Law. Book page 48-49

Newton s 3 rd Law. Book page 48-49 Newton s 3 rd Law Book page 48-49 14/9/2016 cgrahamphysics.com 2016 Newton s 2 nd Law problem Newton s second law does not always work: - does not work when applied to atoms and molecules - does not work

More information

variable Formula S or v SI variable Formula S or v SI 4. How is a Newton defined? What does a Newton equal in pounds?

variable Formula S or v SI variable Formula S or v SI 4. How is a Newton defined? What does a Newton equal in pounds? Newton s Laws 1 1. Define mass variable Formula S or v SI 2. Define inertia, how is inertia related to mass 3. What is a Force? variable Formula S or v SI 4. How is a Newton defined? What does a Newton

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

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

Chap. 4: Newton s Law of Motion

Chap. 4: Newton s Law of Motion Chap. 4: Newton s Law of Motion And Chap.5 Applying Newton s Laws (more examples) Force; Newton s 3 Laws; Mass and Weight Free-body Diagram (1D) Free-body Diagram (1D, 2 Bodies) Free-body Diagram (2D)

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

Examples Newton's Laws and Friction

Examples Newton's Laws and Friction Examples Newton's Laws and Friction 1. A 10.0 kg box is sitting on a table. (A) If a 49 N force is required to overcome friction and start the block moving, calculate the coefficient of static friction.

More information

Mass & Weight. weight a force acting on a body due to the gravitational attraction pulling that body to another. NOT constant.

Mass & Weight. weight a force acting on a body due to the gravitational attraction pulling that body to another. NOT constant. Mass & Weight mass how much stuff a body has. Doesn t change. Is responsible for the inertial properties of a body. The greater the mass, the greater the force required to achieve some acceleration: Fnet

More information

LECTURE 12 FRICTION & SPRINGS. Instructor: Kazumi Tolich

LECTURE 12 FRICTION & SPRINGS. Instructor: Kazumi Tolich LECTURE 12 FRICTION & SPRINGS Instructor: Kazumi Tolich Lecture 12 2 Reading chapter 6-1 to 6-2 Friction n Static friction n Kinetic friction Springs Origin of friction 3 The origin of friction is electromagnetic

More information

Main points of today s lecture: Normal force Newton s 3 d Law Frictional forces: kinetic friction: static friction Examples. Physic 231 Lecture 9

Main points of today s lecture: Normal force Newton s 3 d Law Frictional forces: kinetic friction: static friction Examples. Physic 231 Lecture 9 Main points of today s lecture: Normal force Newton s 3 d Law Frictional forces: kinetic friction: static friction Examples. Physic 3 Lecture 9 f N k = µ k f N s < µ s Atwood s machine Consider the Atwood

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

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

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

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

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

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

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

Circle the correct answer. For those questions involving calculations, working MUST be shown to receive credit.

Circle the correct answer. For those questions involving calculations, working MUST be shown to receive credit. Dynamics Assignment 3 Name: Multiple Choice. Circle the correct answer. For those questions involving calculations, working MUST be shown to receive credit. 1. Which statement is always true regarding

More information

Solving two-body problems with Newton s Second Law. Example Static and Kinetic Friction. Section 5.1 Friction 10/15/13

Solving two-body problems with Newton s Second Law. Example Static and Kinetic Friction. Section 5.1 Friction 10/15/13 Solving two-body problems with Newton s Second Law You ll get multiple equations from the x and y directions, these equations can be solved simultaneously to find unknowns 1. Draw a separate free body

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

PHYSICS. Chapter 7 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc.

PHYSICS. Chapter 7 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 7 Lecture RANDALL D. KNIGHT Chapter 7 Newton s Third Law IN THIS CHAPTER, you will use Newton s third law to understand how objects

More information

Welcome back to Physics 211

Welcome back to Physics 211 Welcome back to Physics 211 Today s agenda: Weight Friction Tension 07-1 1 Current assignments Thursday prelecture assignment. HW#7 due this Friday at 5 pm. 07-1 2 Summary To solve problems in mechanics,

More information

PHYSICS 220 Lecture 04 Forces and Motion in 1 D Textbook Sections

PHYSICS 220 Lecture 04 Forces and Motion in 1 D Textbook Sections PHYSICS 220 Lecture 04 Forces and Motion in 1 D Textbook Sections 3.2 3.6 Lecture 4 Purdue University, Physics 220 1 Last Lecture Constant Acceleration x = x 0 + v 0 t + ½ at 2 v = v 0 + at Overview v

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

Review: Advanced Applications of Newton's Laws

Review: Advanced Applications of Newton's Laws Review: Advanced Applications of Newton's Laws 1. The free-body diagram of a wagon being pulled along a horizontal surface is best represented by a. A d. D b. B e. E c. C 2. The free-body diagram of a

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

Chapter 4. Forces and Newton s Laws of Motion. continued

Chapter 4. Forces and Newton s Laws of Motion. continued Chapter 4 Forces and Newton s Laws of Motion continued Quiz 3 4.7 The Gravitational Force Newton s Law of Universal Gravitation Every particle in the universe exerts an attractive force on every other

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

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

Isaac Newton ( ) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity

Isaac Newton ( ) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity Isaac Newton (1642-1727) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of

More information

General Physics I Spring Applying Newton s Laws

General Physics I Spring Applying Newton s Laws General Physics I Spring 2011 pplying Newton s Laws 1 Friction When you push horizontally on a heavy box at rest on a horizontal floor with a steadily increasing force, the box will remain at rest initially,

More information

Newton s First Law and IRFs

Newton s First Law and IRFs Goals: Physics 207, Lecture 6, Sept. 22 Recognize different types of forces and know how they act on an object in a particle representation Identify forces and draw a Free Body Diagram Solve 1D and 2D

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

Physics Mechanics. Lecture 11 Newton s Laws - part 2

Physics Mechanics. Lecture 11 Newton s Laws - part 2 Physics 170 - Mechanics Lecture 11 Newton s Laws - part 2 Newton s Second Law of Motion An object may have several forces acting on it; the acceleration is due to the net force: Newton s Second Law of

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 PowerPoints. Chapter 4 Physics: for Scientists & Engineers, with Modern Physics, 4th edition Giancoli

Lecture PowerPoints. Chapter 4 Physics: for Scientists & Engineers, with Modern Physics, 4th edition Giancoli Lecture PowerPoints Chapter 4 Physics: for Scientists & Engineers, with Modern Physics, 4th edition Giancoli 2009 Pearson Education, Inc. This work is protected by United States copyright laws and is provided

More information

Chapter 6. Applications of Newton s Laws

Chapter 6. Applications of Newton s Laws Chapter 6 Applications of Newton s Laws P. Lam 7_11_2018 Learning Goals for Chapter 5 Learn how to apply Newton s First Law & Second Law. Understand the cause of apparent weight and weightlessness Learn

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

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

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

Bell Ringer: What is Newton s 3 rd Law? Which force acts downward? Which force acts upward when two bodies are in contact?

Bell Ringer: What is Newton s 3 rd Law? Which force acts downward? Which force acts upward when two bodies are in contact? Bell Ringer: What is Newton s 3 rd Law? Which force acts downward? Which force acts upward when two bodies are in contact? Does the moon attract the Earth with the same force that the Earth attracts the

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

Newton s Laws of Motion. Chapter 4

Newton s Laws of Motion. Chapter 4 Newton s Laws of Motion Chapter 4 Newton s First Law of Motion Force A force is a push or pull. An object at rest needs a force to get it moving; a moving object needs a force to change its velocity. Force

More information

24/06/13 Forces ( F.Robilliard) 1

24/06/13 Forces ( F.Robilliard) 1 R Fr F W 24/06/13 Forces ( F.Robilliard) 1 Mass: So far, in our studies of mechanics, we have considered the motion of idealised particles moving geometrically through space. Why a particular particle

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

Friction (static & Kinetic) Review

Friction (static & Kinetic) Review Friction (static & Kinetic) Review 1. Sand is often placed on an icy road because the sand A) decreases the coefficient of friction between the tires of a car and the road B) increases the coefficient

More information

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

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

Physics Chapter 4 Newton s Laws of Motion

Physics Chapter 4 Newton s Laws of Motion Physics Chapter 4 Newton s Classical Mechanics Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting on them Conditions when Classical

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

Chapter 5 Lecture. Pearson Physics. Newton's Laws of Motion. Prepared by Chris Chiaverina Pearson Education, Inc.

Chapter 5 Lecture. Pearson Physics. Newton's Laws of Motion. Prepared by Chris Chiaverina Pearson Education, Inc. Chapter 5 Lecture Pearson Physics Newton's Laws of Motion Prepared by Chris Chiaverina Chapter Contents Newton's Laws of Motion Applying Newton's Laws Friction Newton's Laws of Motion Two of the most important

More information

Physics 1100: 2D Kinematics Solutions

Physics 1100: 2D Kinematics Solutions Questions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Physics 1100: 2D Kinematics Solutions 1. In the diagrams below, a ball is on a flat horizontal surface. The initial velocity

More information

You may use g = 10 m/s 2, sin 60 = 0.87, and cos 60 = 0.50.

You may use g = 10 m/s 2, sin 60 = 0.87, and cos 60 = 0.50. 1. A child pulls a 15kg sled containing a 5kg dog along a straight path on a horizontal surface. He exerts a force of a 55N on the sled at an angle of 20º above the horizontal. The coefficient of friction

More information

Concept of Force Challenge Problem Solutions

Concept of Force Challenge Problem Solutions Concept of Force Challenge Problem Solutions Problem 1: Force Applied to Two Blocks Two blocks sitting on a frictionless table are pushed from the left by a horizontal force F, as shown below. a) Draw

More information

Figure 5.1a, b IDENTIFY: Apply to the car. EXECUTE: gives.. EVALUATE: The force required is less than the weight of the car by the factor.

Figure 5.1a, b IDENTIFY: Apply to the car. EXECUTE: gives.. EVALUATE: The force required is less than the weight of the car by the factor. 51 IDENTIFY: for each object Apply to each weight and to the pulley SET UP: Take upward The pulley has negligible mass Let be the tension in the rope and let be the tension in the chain EXECUTE: (a) The

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. FLEX Physical Science AP Physics C Newton's Laws --- Conceptual Questions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) You swing a bat and hit

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

PHYSICS 231 Laws of motion PHY 231

PHYSICS 231 Laws of motion PHY 231 PHYSICS 231 Laws of motion 1 Newton s Laws First Law: If the net force exerted on an object is zero the object continues in its original state of motion; if it was at rest, it remains at rest. If it was

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

Example. F and W. Normal. F = 60cos 60 N = 30N. Block accelerates to the right. θ 1 F 1 F 2

Example. F and W. Normal. F = 60cos 60 N = 30N. Block accelerates to the right. θ 1 F 1 F 2 Physic 3 Lecture 7 Newton s 3 d Law: When a body exerts a force on another, the second body exerts an equal oppositely directed force on the first body. Frictional forces: kinetic friction: fk = μk N static

More information

Friction forces. Lecture 8. Chapter 6. Physics I. Course website:

Friction forces. Lecture 8. Chapter 6. Physics I. Course website: Lecture 8 Physics I Chapter 6 Friction forces Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsi Today we are going to discuss: Chapter 6: Some leftover (Ch.5) Kinetic/Static Friction:

More information

Dynamic equilibrium: object moves with constant velocity in a straight line. = 0, a x = i

Dynamic equilibrium: object moves with constant velocity in a straight line. = 0, a x = i Dynamic equilibrium: object moves with constant velocity in a straight line. We note that F net a s are both vector quantities, so in terms of their components, (F net ) x = i (F i ) x = 0, a x = i (a

More information

Student AP Physics 1 Date. Newton s Laws B FR

Student AP Physics 1 Date. Newton s Laws B FR Student AP Physics 1 Date Newton s Laws B FR #1 A block is at rest on a rough inclined plane and is connected to an object with the same mass as shown. The rope may be considered massless; and the pulley

More information

If there is nothing pushing on an object, it will not move. If there is nothing pushing on an object, it will not stop. The List:

If there is nothing pushing on an object, it will not move. If there is nothing pushing on an object, it will not stop. The List: If there is nothing pushing on an object, it will not move. If there is nothing pushing on an object, it will not stop. The List: No Push No Go No Push No Stop No Push No Speed Up No Push No Slow Down

More information

Lecture 4. Newton s 3rd law and Friction

Lecture 4. Newton s 3rd law and Friction Lecture 4 Newton s 3rd law and Friction Newtons First Law or Law of Inertia If no net external force is applied to an object, its velocity will remain constant ("inert"). OR A body cannot change its state

More information

Phys101 Lecture 5 Dynamics: Newton s Laws of Motion

Phys101 Lecture 5 Dynamics: Newton s Laws of Motion Phys101 Lecture 5 Dynamics: Newton s Laws of Motion Key points: Newton s second law is a vector equation Action and reaction are acting on different objects Free-Body Diagrams Ref: 4-1,2,3,4,5,6,7. Page

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

Exercises on Newton s Laws of Motion

Exercises on Newton s Laws of Motion Exercises on Newton s Laws of Motion Problems created by: Raditya 1. A pendulum is hanging on a ceiling of a plane which is initially at rest. When the plane prepares to take off, it accelerates with a

More information

Phys101 Second Major-162 Zero Version Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: N Ans:

Phys101 Second Major-162 Zero Version Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: N Ans: Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: 1 Q1. Only two horizontal forces act on a 3.0 kg body that can move over a frictionless floor. One force is 20 N, acting due east, and the other

More information

= 40 N. Q = 60 O m s,k

= 40 N. Q = 60 O m s,k Sample Exam #2 Technical Physics Multiple Choice ( 6 Points Each ): F app = 40 N 20 kg Q = 60 O = 0 1. A 20 kg box is pulled along a frictionless floor with an applied force of 40 N. The applied force

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

Help Desk: 9:00-5:00 Monday-Thursday, 9:00-noon Friday, in the lobby of MPHY.

Help Desk: 9:00-5:00 Monday-Thursday, 9:00-noon Friday, in the lobby of MPHY. Help Desk: 9:00-5:00 Monday-Thursday, 9:00-noon Friday, in the lobby of MPHY. SI (Supplemental Instructor): Thomas Leyden (thomasleyden@tamu.edu) 7:00-8:00pm, Sunday/Tuesday/Thursday, MPHY 333 Chapter

More information

Review: Newton s Laws

Review: Newton s Laws More force was needed to stop the rock Review: Newton s Laws F r 1 F r F r 3 F r 4 2 Newton s First Law The velocity of an object does not change unless a force acts on the object Newton s Second Law:

More information

7. Two forces are applied to a 2.0-kilogram block on a frictionless horizontal surface, as shown in the diagram below.

7. Two forces are applied to a 2.0-kilogram block on a frictionless horizontal surface, as shown in the diagram below. 1. Which statement about the movement of an object with zero acceleration is true? The object must be at rest. The object must be slowing down. The object may be speeding up. The object may be in motion.

More information

(35+70) 35 g (m 1+m 2)a=m1g a = 35 a= =3.27 g 105

(35+70) 35 g (m 1+m 2)a=m1g a = 35 a= =3.27 g 105 Coordinator: Dr. W. L-Basheer Monday, March 16, 2015 Page: 1 Q1. 70 N block and a 35 N block are connected by a massless inextendable string which is wrapped over a frictionless pulley as shown in Figure

More information

PHYSICS - CLUTCH CH 04: INTRO TO FORCES (DYNAMICS)

PHYSICS - CLUTCH CH 04: INTRO TO FORCES (DYNAMICS) !! www.clutchprep.com FORCE, APPLIED FORCE, TENSION A force is either a push or a pull. Unit = ( ) - We ll represent all forces as a We ll refer to generic forces as forces. - Usually on an object by a

More information

(a) On the dots below that represent the students, draw and label free-body diagrams showing the forces on Student A and on Student B.

(a) On the dots below that represent the students, draw and label free-body diagrams showing the forces on Student A and on Student B. 2003 B1. (15 points) A rope of negligible mass passes over a pulley of negligible mass attached to the ceiling, as shown above. One end of the rope is held by Student A of mass 70 kg, who is at rest on

More information