1) Your mass on the moon will be about one-sixth of your mass on Earth.

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1 Exam Name TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) Your mass on the moon will be about one-sixth of your mass on Earth. 1) 2) The kinetic coefficient of friction is usually larger than the static coefficient of friction. 2) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 3) You are standing in a moving bus, and you suddenly fall backward. You can imply from this that 3) the bus's A) speed remained the same, but it's turning to the right. B) velocity increased. C) the bus stopped. D) speed remained the same, but it's turning to the left. E) velocity decreased. 4) If you blow up a balloon, and then release it, the balloon will fly away as the air rushes out. This is 4) an illustration of A) Newton's First Law. B) Galileo's Law of Inertia. C) Newton's Law of Universal Gravitation. D) Newton's Second Law. E) Newton's Third Law. 5) When you sit on a chair, the reaction to your weight is 5) A) the Earth being pulled up. B) the floor pushing up on the chair. C) the chair pushing on you. D) zero if in equilibrium. E) your push down on the chair. 6) An arrow is shot straight up. At the top of its path, the net force acting on it is 6) A) greater than zero, but less than its weight. B) equal to its weight. C) horizontal. D) instantaneously equal to zero. E) greater than its weight. 1

2 7) Two toy cars (16 kg and 2 kg) are released simultaneously on an inclined plane that makes an angle 7) of 30 with the horizontal. Which statement best describes their acceleration after being released? A) The 16-kg car accelerates 8 times faster than the 2-kg car. B) The 2-kg car accelerates 8 times faster than the 16-kg car. C) Both cars accelerate at a rate of g. D) Both cars accelerate at a rate of g sin(30 ). E) Both cars accelerate at a rate of 8 g. 8) You fall, while skiing, and one ski (of weight W) loosens and slides down an icy slope (assume no 8) friction), which makes an angle with the horizontal. The force that pushes it down along the hill is A) zero; it moves with constant velocity. B) W tan. C) W cos. D) W sin. E) W. 9) To push a piece of heavy furniture across the carpet usually takes more force to get it moving than 9) it takes to keep is moving. This is because A) of Newton's second law. B) of Newton's first law. C) the static coefficient of friction is larger than the kinetic coefficient. D) the kinetic coefficient of friction is larger than the static coefficient. E) of Newton's third law. 10) An object is dropped from a helicopter. When it reaches terminal velocity 10) A) gravity no longer acts upon it. B) the acceleration finally reaches g. C) the acceleration of gravity, g, becomes 0. D) the total force is zero. E) all of the upward forces add up to zero. 11) If a force accelerates 4.5 kg at 40.m/s2, that same force would accelerate 18. kg by how much? 11) A) 0.18 km/s2 B) 10. m/s2 C) 40. m/s2 D) 0.16 km/s2 E) 32. ft/s2 12) An antitank weapon fires a 3.0 kg rocket which acquires a speed of 50. m/s after traveling 90. cm 12) down a launching tube. Assuming the rocket was accelerated uniformly, what force acted on it? A) 4.2 kn B) 2.0 kn C) 3.6 kn D) 5.8 kn E) 2.8 kn 2

3 13) An elevator weighing 10,000. N is supported by a steel cable. Determine the tension in the cable 13) when the elevator is accelerated upward at 3.0 m/s2. (g = 9.8 m/s2) A) 7.0 kn B) 13. kn C) 11. kn D) 40. kn E) 10. kn 14) A 42.0 kg block of ice slides down the plane incline 34.0 in Figure ) Figure 4-12 Assuming friction is negligible, what is the acceleration of the block down the incline? A) 6.61 m/s2 B) 5.48 m/s2 C) 2.73 m/s2 D) 8.12 m/s2 E) 9.80 m/s2 15) A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. How large 15) is the coefficient of kinetic friction, µk, if the plane makes an angle of 25. with the horizontal? A) 0.91 B) 0.47 C) 1.2 D) 0.42 E) ) James is twirling a rock around a horizontal circle on the end of a string. Figure 7-2 is a top view 16) (motion is counterclockwise). Figure 7-2 If the speed is constant what is the acceleration at point A? A) v / r B) r v2 C) centripetal D) centrifugal E) zero 3

4 17) Does the centripetal force acting on an object do work on the object? 17) A) yes, because the force and the displacement of the object are perpendicular B) no, because the object has constant speed C) no, because the force and the displacement of the object are perpendicular D) yes, since a force acts and the object moves, and work is force times distance E) yes, since it takes energy to turn an object 18) A race car, traveling at a constant speed of 50. m/s, drives around a circular track of radius 250. m. 18) What magnitude acceleration does it experience? A) 10. m/s2 B) zero C) 1.0 m/s2 D) 2.2 m/s2 E) 0.63 km/s2 19) What is the centripetal acceleration of a point on the perimeter of a bicycle wheel of diameter ) cm when the bike is moving 8.0 m/s? A) 66 m/s2 B) 91 m/s2 C) m/s2 D) m/s2 E) m/s2 20) Which of the following is not a unit of work? 20) A) N-m B) J C) Kg-m/s D) Kw-h E) W-s 21) Can work be done on a system if there is no motion? 21) A) No, since work involves a non-zero displacement. B) Yes, since motion is only relative. C) No, since a system which is not moving has no energy. D) Yes, if the sum of the external forces is zero. E) Yes, if an external force is acting on the system. 22) You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up 22) with the sign of the work done by gravity while it goes down. A) Work up is +, and the work down is -. B) Work up is -, and the work down is -. C) Work up is -, and the work down is +. D) Work up is +, and the work down is +. 4

5 23) On a plot of F vs. x, what represents the work done by the force F? 23) A) the product of the maximum force times the maximum x B) the area under the curve C) the slope of the curve D) the maximum F times minimum x E) the length of the curve 24) Consider an ideal elastic spring. The spring constant is 24) A) proportional to the mass attached to the spring. B) inversely proportional to the displacement. C) proportional to displacement from equilibrium. D) inversely proportional to the applied force. E) none of the other answers. 25) A leaf falls from a tree. Compare its kinetic energy K to its potential energy U. 25) A) K increases, and U increases. B) K increases, and U decreases. C) K decreases, and U increases. D) K decreases, and U decreases. E) K and U remain constant. 26) To accelerate your car at a constant acceleration, the car's engine must 26) A) maintain a constant turning speed. B) maintain a constant power output. C) develop ever-increasing power. D) develop ever-decreasing power. 27) Matthew pulls his little sister Sarah in a sled on an icy surface (assume no friction), with a force of 27) 60.0 Newtons at an angle of 37.0 upward from the horizontal. If he pulls her a distance of 12.0 m, the work he does is A) 433 J B) kj C) 185 J D) 575 J E) 720 J 28) A 4.0 kg box of fruit slides 8.0 m down a ramp, inclined at 30. from the horizontal. If the box slides 28) at a constant velocity of 5.0 m/s, the work done by gravity is A) kj. B) -78. J. C) 0.16 kj. D) zero. E) +78. J. 5

6 29) A container of water is lifted vertically 3.0 m, then returned to its original position. If the total 29) weight is 30. N, how much work was done? A) 0.18 kj B) 45 J C) 0.90 kj D) 90 J E) No work was done. Figure ) The force that a squirrel exerts on a nut it has found is observed over a 10. second interval, as 30) shown in Figure 5-4. How much work did the squirrel do during that 10. s? A) 25. J B) 12.5 J C) zero D) 22. J E) 50. J 31) The resultant force you exert while pressing a key on the keyboard of your new computer, for a 31) 1.0-s period, is plotted in Figure 5-5. Figure 5-5 How much work did you do during this 1-s interval? A) zero B) 22. J C) -25. J D) 12.5 J E) 50. J 6

7 32) A 10. kg mass, hung onto a spring, causes the spring to stretch 2.0 cm. The spring constant is 32) A) 5.0 N/cm B) N/cm C) 49 N/cm D) 0.20 N/cm E) 20. N/m 33) A spring is characterized by a spring constant of 60. N/m. How much potential energy does it store, 33) when stretched by 1.0 cm? A) 60. J B) J C) 0.3 J D) 6.0 µj E) 600. J NOTE: The following question(s) refer(s) to the Cyclone, the famous roller coaster ride at Coney Island, shown in the sketch. Assume no friction. Figure ) Refer to Figure 5-6. How much work was required to bring the 1000-kg roller coaster from point P 34) to rest at point Q at the top of the 50. m peak? A) 0.49 MJ B) 0.25 MJ C) 50. kj D) 75. kj E) 32. kj 35) A 1.0 kg flashlight falls to the floor. At the point during its fall when it is 0.70 m above the floor, its 35) potential energy exactly equals its kinetic energy. How fast is it moving? A) 6.9 m/s B) 45 m/s C) 14 m/s D) 3.7 m/s E) 9.8 m/s 7

8 36) Two identical masses are attached by a light string that passes over a small pulley, as shown in 36) Figure 4-3. Figure 4-3 The table and the pulley are frictionless. The masses are moving A) with an acceleration greater than g. B) at constant speed. C) with an acceleration equal to g. D) with an acceleration less than g. 37) A N gondola car, at a ski lift, is temporarily suspended at the halfway point, causing the wire 37) to sag by 37.0 below the horizontal, as shown in Figure Figure 4-10 The tension in the cable is A) N B) N C) N D) N E) N 8

9 38) Consider a 42.0 kg block of ice sliding down the 34.0 plane, as shown in Figure ) Figure 4-13 Assuming the kinetic coefficient of friction is 0.060, what is the acceleration of the block down the incline? A) 9.74 m/s2 B) 2.73 m/s2 C) 6.56 m/s2 D) 5.00 m/s2 E) 8.06 m/s2 39) A horizontal force of 5.0 N accelerates a 4.0 kg mass, from rest, at a rate of 39) 0.50 m/s2 in the positive direction. What friction force acts on the mass? A) -3.0 N B) -3.3 N C) -2.0 N D) +3.0 N E) +2.0 N 40) A toolbox, of mass M, is resting on a flat board, as shown in Figure 4-5. One end of the board is 40) lifted up until the toolbox just starts to slide. Figure 4-5 The angle that the board makes with the horizontal, for this to occur, depends on the A) coefficient of kinetic friction, µk. B) acceleration of gravity, g. C) coefficient of static friction, µs. D) mass, M. E) all of the above quantities. 9

10 Use the Figure 4-11 and the information below to answer the following question(s). A train consists of a caboose (mass = 1000 kg), a car (mass 2000 kg), and an engine car (mass 2000 kg). Figure ) Refer to Figure If the train has an acceleration of 5.50 m/s2, then the tension force in the 41) coupling between the middle car and the engine car is A) 5.50 kn. B) 27.5 kn. C) 11.0 kn. D) 8.25 kn. E) 16.5 kn. 42) The work energy theorem says 42) A) the net work done plus the final kinetic energy is the initial kinetic energy. B) final kinetic energy plus the net work done is the initial kinetic energy. C) the net work done plus the initial kinetic energy is the final kinetic energy. D) the net work done minus the initial kinetic energy is the final kinetic energy. E) the net work done is equal to the initial kinetic energy less the final energy. Use Figure 5-2 below to answer the following question(s). Figure ) In Figure 5-2, showing a pendulum, at what position is the potential energy maximum? 43) A) A B) B C) C 44) A toy rocket, weighing 10. N, blasts off from ground level. At the exact top of its trajectory, its 44) energy is 140. J. To what vertical height does it rise? A) 14. m B) 12. m C) 1.4 m D) 1.4 km E) 0.12 km 10

11 45) Assuming negligible friction, what spring constant would be needed by the spring in a "B-B gun" 45) to fire a 10. gram pellet to a height of 100 meters if the spring is initially compressed 10. cm? A) 20. N/m B) N/m C) 200. N/m D) 20. N/cm E) N/cm 46) A skier, of mass 60. kg, pushes off the top of a frictionless hill with an initial speed of 4.0 m/s. How 46) fast will she be moving after dropping 10. m in elevation? A) 0.20 km/s B) 15. m/s C) 49. m/s D) 0.15 km/s E) 10. m/s Figure ) The force that a squirrel exerts on a nut it has found is observed over a 10. second interval, as 47) shown in Figure 5-8. What was the average power exerted by the squirrel? A) 2.5 W B) 2.2 W C) 1.3 W D) 5.0 W E) zero 48) If a spring-operated gun can shoot a pellet to a height of 100. m on Earth, how high could the pellet 48) rise if fired on the moon? A) 100. m B) 16.7 m C) m D) 600. m E) 3.60 km 49) A space station of diameter 40. meters is turning about its axis at a constant rate. What is the period 49) of revolution of the space station if the outer rim experiences an acceleration of 2.5 m/s2? A) 14. s B) 10. s C) 11. s D) 18. s E) 13. s 50) A jet plane flying 600. m/s experiences an acceleration of 4.0 g when pulling out of the dive. What is 50) the radius of curvature of the loop in which the plane is flying? A) 5.8 km B) 1.2 km C) 0.64 km D) 7.0 km E) 9.2 km 11

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