Phys 111 Exam October 18, 016 Name Section University ID Please fill in your computer answer sheet as follows: 1) Use your previous answer sheet and start with 1. Note problem number of the second exam starts with 1! ) Make sure that you filled in the circles on the sheet corresponding to the letters or numbers of your name, ID and section. 3) If you use a new answer sheet, follow the following instruction. 4) Fill in the circles on the sheet corresponding to the letters or numbers of your name, ID and section with a # pencil. 5) In the NAME grid, fill in your last name, leave one blank space, then your first name. 6) Write your ID number in the IDENTIFICATION NUMBER section of the sheet. 7) Write your recitation section number in the spaces K, L in the SPECIAL CODES section. Single digits should be preceded by a 0 (e.g. section 1 is written as 01). Note (a) Use g = 9.81 m/s if needed. (b) There are 0 multiple choice problems. (c).0 hour Exam (no one can leave before 9:15 PM). (d) Formula sheets are available (attached at the last two pages). (e) Record sheet is attached after the 0 exam problems. _ DO NOT USE CELL PHONES. Good Luck!!! 1
1. Neglecting air resistance, when you toss a stone straight up in the air from Earth's surface, which of the following statements is true for the upward motion of the stone. A) The stone's total energy increases. B) The stone's kinetic and gravitational potential energies increase simultaneously. C) The stone's kinetic and gravitational potential energies decrease simultaneously. D) The stone's kinetic energy decreases while its gravitational potential energy increases. E) The stone's kinetic energy increases while its gravitational potential energy decreases.. The ratio of kinetic energy of object A to the kinetic energy of object B is :1. Object A is moving with a speed of 6.0 m/s and object B is moving with a speed of 3.0 m/s. If the mass of object A is 4.0 kg then what is the mass of object B? A).0 kg B) 4.0 kg C) 8.0 kg D) 18 kg E) 16 kg 3 If both mass and velocity of a ball are tripled, the kinetic energy of the ball is increased by a factor of A) 1 B) 3 C) 6 D) 9 E) 7 4 A.9 kg block slides with a speed of 1.6 m/s on a frictionless horizontal surface until it encounters a spring. If the block compresses the spring 4.8 cm before coming to rest, what is the force constant of the spring? A) 1.6 kn/m B) 96 N/m C) 3. kn/m D) 0.3 N/m E) 0.96 N/m
5 On an amusement park ride, passengers are seated in a horizontal circle of radius 7.5 m. The seats begin from rest and are uniformly accelerated for 1 seconds to a maximum rotational speed of 1.4 rad/s. What is the tangential acceleration of the passengers during the first 1 s of the ride? A) 0.067 m/s B) 0.50 m/s C) 1.4 m/s D) 7.5 m/s E)11 m/s 6 An object of 1.0 kg mass is pulled up an inclined plane by a constant force of 10 N that causes a displacement of 0.50 m. The angle of inclination with the horizontal is 30. Neglect friction. What is the work done by the 10 N force on the object along the inclined plane? A) 4.3 J B) 4.3 kg m/s C) 5.0 J D).5 J E).5 kg m/s 7. An object of mass = kg is pulled by a constant force F = 4 N for a horizontal distance of m as shown above. Neglect friction. What is the work done along the +x-axis? A) 9 J B) 8 J C) 5 J D) 7 J E) J 8. A 0-kg object is lifted at a constant speed through a height of 4 m by a crane. If the crane takes a total time of 1.8 seconds to lift this object, what is the average power required? A) 5 kw B) 50 kw C) 75 kw D) 100 kw E) 150 kw 3
9. An object is under the influence of a force as represented by the force vs. position graph in figure above. What is the work done as the object moves from 0 m to 6 m? A) 70 J B) 30 J C) 0 J D) 40 J E) 0 J 30. Jill of the Jungle swings on a vine that is 6.90 m long. What is the tension in the vine if Jill, whose mass is 63.0 kg, is moving at.4 m/s when the vine is vertical? A) 55N B) 618 N C) 5.5 N D) 670 N E) 105 N 31. A.0-kg ball is moving with a constant speed of 5 m/s in a horizontal circle whose radius is 50 cm. What is the centripetal acceleration of the ball? A) 0 m/s B) 10 m/s C) 0 m/s D) 50 m/s E) 100 m/s 4
3. You need to load a crate of mass m onto the bed of a truck. One possibility is to lift the crate straight up over a height h, equal to height of the truck's bed. The work done in this case is W 1. The other possibility is to slide the crate up the frictionless ramp of length L as shown in the above figure. In this case you perform work W. What statement is true? A) W 1 < W B) W 1 = W C) W 1 > W D) No simple relationship exists between W 1 and W. E) There is not enough information to solve this problem. 33. A figure skater is spinning slowly with arms outstretched. She brings her arms in close to her body and her moment of inertia decreases by 1/. By what factor does her angular momentum change? A) 4 B) C) 1/ D) 1/4 E) It doesn't change. 34. A 1.0 kg disk with a radius of 10.0 cm rolls without slipping. If linear speed of the disk is 1.41 m/s, what is total kinetic energy of the disk? The moment of inertia for a disk is 0.006 kgm. A) 0.595 J B) 1.79 J C) 1.19 J D).98 J E) There is not enough information to solve this problem. 5
35. An inelastic collision of two objects is characterized by the following. A) Total momentum of the system is conserved. B) Total kinetic energy of the system remains constant. C) Both A and B are true. D) Neither A nor B are true. 36. A batter hits a 0.140-kg baseball that was approaching him at 40.0 m/s and, as a result, the ball leaves the bat at 30.0 m/s in the direction of the pitcher. What is the magnitude of the impulse delivered to the baseball? A) 9.80 Ns B) 1.40 Ns C) 5.60 Ns D) 4.90 Ns E) 7.00 Ns 37. An 8.0 kg-diver stands at the edge of a light 5.00-m diving board, which is supported by two pillars 1.60 m apart, as shown in the above figure. Find the force exerted by pillar A. A) 1.71 kn downwards B) 1.71 kn upwards C).51 kn downwards D).51 kn upwards E) 3.44 kn upwards 6
38. To throw a curve ball, a pitcher gives the ball an initial angular speed of 36.0 rad/s. When the catcher gloves the ball 0.595 s later, its angular speed has decreased to 34. rad/s. What is the ball s angular acceleration, assuming the acceleration is constant. A) 6.06 rad/s B) 57.4 rad/s C) 60.5 rad/s D) 3.03 rad/s E) 0 rad/s 39. A child is trying to stack two uniform wooden blocks, 1 cm in length, so they will protrude as much as possible over the edge of a table, without tipping over, as shown above. What is the maximum possible overhang distance? A) 5 cm B) 6 cm C) 7 cm D) 8 cm E) 9 cm 40. An object of mass 5.00 kg starts at rest from the top of a rough inclined plane of height 10.0 m as shown in the figure above. If the work done by the force of friction is -100 J, what is the speed of the object as it reaches the bottom of the inclined plane? A) 10.5 m/s B) 1.5 m/s C) 14.0 m/s D) 15.4 m/s E) 16.5 m/s 7
Record Sheet of Exam #, Physics 111, Fall 016 You may fill in this sheet with your choices and take it with you for comparison to the posted answers. 1 31 3 3 33 4 34 5 35 6 36 7 37 8 38 9 39 30 40 8
Physics 111, Fall 016: Formula sheet Vectors: A Acos A Asin x y 1 x y tan Ay / Ax A A A Linear Motion: x x f xi v x / t a v / t v v0 at 1 1 x v0t a t v v0 a x x v0 v t Forces: N Fnet mm 1 Fnet F1 F F3 Fi a Fg G i1 m r Weight W mg fk kn fs sn Fx kx Work and Energy: W ( F cos ) d KE mv / PE mgh P work / t Fd / t Fv Etot KE PE PE kx / Linear momentum and impulse: p mv Ft p I Ft p p 0 p f pi x m x / m cm i i i y m y / m cm i i i Uniform Circular Motion: v r / T a v / r c F c mv / r tan v / rg Rotational Kinematics: s/ r / t / t 0 t T / 1 0t t vt r t r 0 ac r Rotational Dynamics: rsinf L 0 Lf Li I miri I L / t L I KE R I / W Gravity: F Gm m r g 1 / G Nm kg 11 6.67 10 / / g 1 PE U Gm m r KE mv / Oscillations about equilibrium: f F kx x Acos( t); vx Asin( t); ax Acos( t) T k 1 1 1 L E KE PE mv kx ka T m g
Waves and Sound: F m P P 1 v f v ; I (10 db)log( I / I 0); I0 10 W / m T L A 4 r n log( A/ B) log( A) log( B); log(10 ) n 1 Doppler Effect for moving source: f0 fs (-) source moving towards observer 1 vs / v v0 Doppler Effect for moving observer: f0 fs 1 (+) observer moving towards source v Constructive Interference: d1 d n; n 1,,3,... Destructive Interference: d1 d n ; n 1,3,5,... Standing waves on a string of length L = Standing waves in a column of air open at both ends of length L L v v n ; fn n ; n 1,,3,... n n L Standing waves in a column of air closed at one end of length L 4 L v v n ; fn n ; n 1,3,5,... n 4L Beat Frequency: fbeat f1 f n Fluids: M F 5 ; P ; Pgauge P Patm ; Patm 1.01 10 N / m V A P P gh 1 F Vg Buoyant fluid m1 m Conversation of Mass : 1 A1 v1 A v t t 1 1 Bernoulli ' s Equation : P v gy P v gy 1 1 1 Temperature and Heat: 5 TC TF 3 TK TC 73.15; L L0T ; V V0T ; Q mct 9 4 8 4 Q ml ; Q ml ; Q / t kat / L; Q / t eat ; 5.67 10 W( m K ) fusion f vaporization v Ideal Gases: 3 PV nrt Nk T; n N / N m / ( mass per mole); R 8.31 J( mol K); k 1.3810 J / K B A B 3 1 3 3 3 NA 6.010 molecules / mole; KEav ( mv ) av kbt; U nrt NkBT Thermodynamics: U Q W; W PV ; CV 3 R / ; CP 3 R / ; CP / CV 5/ 3 W Qh Qc Qc Tc Qh Qc e 1 1 ; COP ; Air Conditioner COP Qh Qh Qh Th W W Q Qh Qc S ; Stotal 0 T T T h c