16. A ball is thrown straight up with an initial speed of 30 m/s. What is its speed after 4.2 s? a. 11 m/s b. 30 m/s c. 42 m/s d.

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1 Page 1 1. If you are driving 90 km/h along a straight road and you look to the side for 3.0 s, how far do you travel during this inattentive period? a. 30 m b. 25 m c. 50 m d. 75 m 2. A polar bear starts at the North Pole. It travels 1.0 km South, then 1.0 km East, then 1.0 km North to return to its starting point. This trip takes 30 min. What was the bear's average velocity? a. 0 km/h b km/h c. 3.0 km/h d. 6.0 km/h 3. Can an object's velocity change direction when its acceleration is constant? a. No, this is not possible because it is always speeding up. b. No, this is not possible because it is always speeding up or always slowing down, but it can never turn around. c. Yes, this is possible, and a rock thrown straight up is an example. d. Yes, this is possible, and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example. 4. A car with good tires on a dry road can decelerate at about 5.0 m/s2 when braking. If the car is traveling at 55 mi/h, how much time does it take the car to stop? a. 9.8 s b. 2.5 s c. 11 s d. 4.9 s 5. An object starts from rest and undergoes uniform acceleration. During the first second it travels 5.0 m. How far will it travel during the third second? a. 5.0 m b. 15 m c. 25 m d. 45 m 6. An object is moving with constant non-zero velocity in the +x axis. The position versus time graph of this object is a. a horizontal straight line. b. a vertical straight line. c. a straight line making an angle with the time axis. d. a parabolic curve.

2 9. An object is thrown upward with a speed of 14 m/s on the surface of planet X where the acceleration due to gravity is 3.5 m/s2. What is the speed of the object after 2.0 s? a. 5.6 m/s b. 7.0 m/s c. 14 m/s d. 21 m/s 10. A skydiver jumps from a high-flying plane. When she reaches terminal velocity, her acceleration a. is essentially zero. b. is in the upward direction. c. is approximately 9.8 m/s2 downward. d. is a constant pointing upward. 11. A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.00 s? a. 9.8 m/s upward. b. 9.8 m/s downward. c. zero d downward. 12. A ball is thrown vertically upward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the second ball to that of the first ball? (How many times higher does the second ball go than the first ball?) a. 4:1 b. 2:1 c. 1.7:1 d. 1.4:1

3 Page A ball is thrown straight up with a speed of 36.0 m/s. How long does it take to return to its starting point? a s b s c s d s 14. Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? a. The one thrown up is traveling faster. b. The one thrown down is traveling faster. c. They are traveling at the same speed. d. It is impossible to tell because the height of the building is not given. 15. A ball is thrown straight up, reaches a maximum height, then falls to its initial height. As the ball is going up, a. both its velocity and its acceleration point upward. b. its velocity points upward and its acceleration points downward. c. its velocity points downward and its acceleration points upward. d. both its velocity and its acceleration points downward. 16. A ball is thrown straight up with an initial speed of 30 m/s. What is its speed after 4.2 s? a. 11 m/s b. 30 m/s c. 42 m/s d. 72 m/s 17. A brick is dropped from the top of a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks. a. The first brick accelerates faster. b. The second brick accelerates faster. c. The two bricks accelerate at the same rate. d. It is impossible to determine from the information given. 18. The slope of a position versus time graph gives a. position b. velocity c. acceleration d. displacement

4 Page The slope of a velocity versus time graph gives a. position b. velocity c. acceleration d. displacment 20. In the graph shown, what is the velocity at t = 2.5 s? a. 0 b. 10 m/s c. 20 m/s d. -40 m/s 21. Which of the following operations will not change a vector? a. Translate it parallel to itself. b. Rotate it. c. Multiply it by a constant factor. d. Add a constant vector to it. 22. Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. When these two vectors are added, the magnitude of the sum a. is 12 m. b. could be as small as 2.0 m, or as large as 12 m. c. is 2.0 m. d. is larger than 12 m.

5 Page A butterfly moves with a speed of v = 12.0 m/s. The y-component of its velocity is 8.00 m/s. The angle between the direction of its motion and the x-axis must be a. 30.0ø b. 41.8ø c. 48.2ø d. 53.0ø 24. Three forces, each having a magnitude of 30 N, pull on an object in directions that are 120ø apart from each other. Which one of the following statements must be true? a. The resultant force is zero. b. The resultant force is greater than 30 N. c. The resultant force is equal to 30 N. d. The resultant force is less than 30 N. 25. If vector A = (-3.0,- 4.0), and vector B = (+3.0,-8.0), what is the magnitude of vector C = A - B? a. 13 b. 16 c. 144 d A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground? a. 100 m b. 162 m c. 177 m d. 283 m 27. A soccerball is kicked with a velocity of 25 m/s at an angle of 45ø above the horizontal. What is the vertical component of its acceleration as it travels along its trajectory? a m/s2 downward b. (9.80 m/s2) X sin (45ø) downward c. (9.80 m/s2) X sin (45ø) upward d. (9.80 m/s2) upward 28. Ignoring air resistance, the horizontal component of a projectile's acceleration a. is zero. b. remains a non-zero constant. c. continuously increases. d. continuously decreases.

6 Page You are traveling at 55 mi/h in the +x axis relative to a straight, level road and pass a car traveling at 45 mi/h. The relative velocity of your car to the other car is a. 10 mi/h. b. -10 mi/h. c. 65 mi/h. d. 35 mi/h. 30. The driver of a motorboat that can move at 10 m/s in still water wishes to travel directly across a river 1.6 km wide in which the current flows at 5.0 m/s. How long will it take to cross the river? a. 5.3 min b. 2.7 min c. 3.1 min d. 1.8 min 31. A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 min 40 s. She is swept downstream 480 m. How fast can she swim in still water? a m/s b. 1.2 m/s c. 1.4 m/s d. 1.8 m/s 32. Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km downstream, in a river flowing at 6.0 km/h? a. 20 min b. 22 min c. 24 min d. 30 min 33. A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 min 40 s. She is swept downstream 480 m. What is the speed of the current? a m/s b. 1.2 m/s c. 1.4 m/s d. 1.8 m/s 34. Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km upstream, in a river flowing at 6.0 km/h? a. 20 min b. 22 min c. 24 min d. 30 min

7 Page Two forces are acting on an object as shown. What is the direction of the resultant force? a. 12ø above -x b. 78ø above -x c. 12ø above +x d. 78ø above +x 36. You are standing in a moving bus, facing forward, and you suddenly fall forward. You can imply from this that the bus's a. velocity increased. b. velocity decreased. c. speed remained the same, but it's turning to the right. d. speed remained the same, but it's turning to the left. 37. An object has a mass of 60 kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth? a. 6.0 kg b. 10 kg c. 60 kg d. 360 kg

8 Page Which of the following describes an object in equilibrium? a. A car moving with constant velocity down a hill. b. The earth orbiting the sun. c. A car going around a curve at constant speed. d. A ball thrown straight up, at the highest point of its path. 39. In the absence of all forces, a moving object will a. slow down and eventually stop. b. move at constant velocity. c. immediately come to rest. d. Cannot determine without more detail. 40. Two cars collide head-on. At every moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on the first. This is an example of a. Newton's First Law. b. Newton's Second Law. c. Newton's Third Law. d. Newton's law of gravitation. 41. An example of a force which acts at a distance is a. tension. b. weight. c. static friction. d. kinetic friction. 42. When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starship will a. stop immediately. b. slowly slow down, and then stop. c. go faster and faster. d. move with constant speed. 43. Starting from rest, a 4.0 kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the body? a. 4.0 N b. 8.0 N c. 16 N d. 32 N 44. A net force F acts on a mass m and produces an acceleration a. What acceleration results if a net force 2F acts on mass 4m? a. 8a b. 4a c. 2a d. a/2

9 Page A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate of 0.50 m/s2 in the positive direction. What friction force acts on the mass? a. 2.0 N b. 3.0 N c. 4.0 N d. 5.0 N 46. A person on a scale rides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerate downward with an acceleration of 4.90 m/s2, what is the reading on the scale? a. 147 N b. 294 N c. 588 N d. 882 N 47. A person on a scale rides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerate upward with an acceleration of 4.90 m/s2, what is the reading on the scale? a. 147 N b. 294 N c. 588 N d. 882 N 48. An object of mass 6000 kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping time if the load is not to slide forward into the cab? a. 5.0 s b. 10 s c. 13 s d. 23 s 49. An object with a mass m slides down a rough 37ø inclined plane where the coefficient of kinetic friction is What is the acceleration of the object? a. 4.3 m/s2 b. 5.9 m/s2 c. 6.6 m/s2 d. 7.8 m/s2

10 Page A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. What is the coefficient of kinetic friction, if the plane makes an angle of 25ø with the horizontal? a b c d In the diagram shown, if the tensions in the ropes are 50 N, what is the mass of the traffic light? a. 3.1 kg b. 4.1 kg c. 6.1 kg d. 8.1 kg

11 Page A traffic light of weight 100 N is supported by two ropes as shown in the figure. What are the tensions in the ropes? a. 50 N b. 63 N c. 66 N d. 83 N

12 Page In the Atwood machine shown, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pulley.) a. 4.9 N b. 5.3 N c. 7.1 N d. 7.5 N

13 Page Two boxes of masses m and 2m are in contact with each other on a frictionless surface. What is the acceleration of the more massive box? a. F/m b. F/(2m) c. F/(3m) d. F/(4m) 55. A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by friction is 1.2X104 N. What is the mass of the car? a. 500 kg b kg c kg d kg 56. A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcycle? a. 719 N b. 2.95X103 N c. 1.31X104 N d. 4.31X104 N

14 Page A car goes around a curve of increasing radius. What happens to the centripetal force on the car? a. It decreases. b. It increases. c. It remains constant. d. It is impossible to predict because it depends on other factors not given here. 58. A pilot executes a vertical dive, then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him is a. less than mg, and pointing up. b. less than mg, and pointing down. c. more than mg, and pointing up. d. more than mg, and pointing down. 59. A curve of radius 80 m is banked at 45ø. Suppose that an ice storm hits, and the curve is effectively frictionless. What is the safe speed with which to take the curve without either sliding up or down? a. 9.4 m/s b. 28 m/s c. 7.8X102 m/s d. The curve cannot be taken safely. 60. A car of mass m goes around a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to a. mg/2 b. mg c. mv2/r d. tan[v2/(rg)] 61. A satellite encircles Mars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is a. zero. b. the same. c. one-third as much. d. one-sixteenth as much

15 Page By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the earth is 6.38X106 m.) a. 0.6 N b. 1.6 N c. 2.6 N d. 3.6 N 63. A satellite is in a low circular orbit about the earth (i.e, it just skims the surface of the earth). What is the speed of the satellite? (The mean radius of the earth is 6.38X106 m.) a. 5.9 km/s b. 6.9 km/s c. 7.9 km/s d. 8.9 km/s 64. The radius of the earth is R. At what distance above the earth's surface will the acceleration of gravity be 4.9 m/s2? a R b R c R d R 65. Consider a small satellite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital velocity? a. v = GM/r b. (GM/r)1/2 c. GM/r2 d. (GM/r2)1/2 66. Two objects, with masses m1 and m2, are originally a distance r apart. The magnitude of the gravitational force between them is F. The masses are changed to 2m1 and 2m2, and the distance is changed to 4r. What is the magnitude of the new gravitational force? a. F/16 b. F/4 c. 16F d. 4F 67. Compared to its mass on the earth, the mass of an object on the moon is a. less. b. more. c. the same. d. half as much.

16 Page What is the gravitational force on a 70-kg person, due to the moon? The mass of the moon is 7.36X1022 kg and the distance to the moon is 3.82X108 m. a N b N c N d N 69. The innermost moon of jupiter orbits the planet with a radius of 422 km and a period of 1.77 days. What is the mass of jupiter? a. 1.3X1027 kg b. 1.5X1027 kg c. 1.7X1027 kg d. 1.9X1027 kg 70. Which of the following is the correct unit of work expressed in SI units? a. kg m/s2 b. kg m2/s c. kg m2/s2 d. kg2 m/s2 71. A 500-kg elavator is pulled upward with a costant force of 5500 N for a distance of 50.0 m. What is the work done by the weight of the elavator? a. 2.75X105 J b X105 J c. 3.00X104 J d X105 J 72. A 500-kg elavator is pulled upward with a costant force of 5500 N for a distance of 50.0 m. What is the net work done on the elavator? a. 2.75X105 J b X105 J c. 3.00X104 J d X105 J 73. If you push twice as hard against a stationary brick wall, the amount of work you do a. doubles b. is cut in half c. remains constant but non-zero d. remains constant at zero

17 Page Does the centripetal force acting on an object do work on the object? a. Yes, since a force acts and the object moves, and work is force times distance. b. Yes, since it takes energy to turn an object. c. No, because the object has constant speed. d. No, because the force and the displacement of the object are perpendicular. 75. You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. a. Work is + on the way up and + on the way down. b. Work is + on the way up and - on the way down. c. Work is - on the way up and + on the way down. d. Work is - on the way up and - on the way down. 76. On a plot of Force versus position (F vs. x), what represents the work done by the force F? a. The slope of the curve b. The length of the curve c. The area under the curve d. The product of the maximum force times the maximum x 77. A horizontal force of 200 N is applied to move a 55-kg cart (initially at rest) across a 10 m level surface. What is the final kinetic energy of the cart? a. 1.0X103 J b. 2.0X103 J c. 2.7X103 J d. 4.0X103 J 78. A horizontal force of 200 N is applied to move a 55-kg cart (initially at rest) across a 10 m level surface. What is the final speed of the cart? a. 73 m/s b. 36 m/s c. 8.5 m/s d. 6.0 m/s 79. Is it possible for a system to have negative potential energy? a. Yes, as long as the total energy is positive. b. Yes, since the choice of the zero of potential energy is arbitrary. c. No, because the kinetic energy of a system must equal its potential energy. d. No, because this would have no physical meaning.

18 Page A spring with a spring constant of 15 N/m is initially compressed by 3.0 cm. How much work is required to compress the spring an additional 4.0 cm? a J b J c J d J 81. An object slides down a frictionless inclined plane. At the bottom, it has a speed of 9.80 m/s. What is the vertical height of the plane? a m b m c m d m 82. A brick is moving at a speed of 3 m/s and a pebble is moving at a speed of 5 m/s. If both objects have the same kinetic energy, what is the ratio of the brick's mass to the rock's mass? a. 25 to 9 b. 5 to 3 c to 4.5 d. 3 to A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building? a. K is equal to U. b. K is greater than U. c. K is less than U. d. It is impossible to tell. 84. A ball drops some distance and loses 30 J of gravitational potential energy. Do not ignore air resistance. How much kinetic energy did the ball gain? a. More than 30 J b. Exactly 30 J c. Less than 30 J d. Cannot be determined from the information given. 85. A 1500-kg car accelerates from 0 to 25 m/s in 7.0 s. What is the average power delivered by the engine? (1 hp = 746 W) a. 60 hp b. 70 hp c. 80 hp d. 90 hp

19 Page Compared to yesterday, you did 3 times the work in one-third the time. To do so, your power output must have been a. the same as yesterday's power output. b. one-third of yesterday's power output. c. 3 times yesterday's power output. d. 9 times yesterday's power output. 87. A person goes up a flight of stairs in 20 s. If the person weighs 600 N, and the vertical height of the stairs is 10 m, what is the person's power output? a. 2.0 W b. 300 W c. 1.2 kw d. 120 kw 88. Two identical 1500-kg cars are moving perpendicular to each other. One moves with a speed of 25 m/s due north and the other moves at 15 m/s due east. What is the total momentum of the system? a. 4.4X104 kgúm/s at 31ø N of E b. 4.4X104 kgúm/s at 59ø N of E c. 6.0X104 kgúm/s at 31ø N of E d. 6.0X104 kgúm/s at 59ø N of E 89. A small object collides with a large object and sticks. Which object experiences the larger magnitude of momentum change? a. the large object b. the small object c. Both objects experienece the same magnitude of momentum change. d. Cannot be determined from the information given. 90. A 70-kg astronaut is space-walking outside the space capsule and is stationary when the tether line breaks. As a means of returning to the capsule he throws his 2.0-kg space hammer at a speed of 14 m/s away from the capsule. At what speed does the astronaut move toward the capsule? a m/s b. 1.5 m/s c. 3.5 m/s d. 5.0 m/s 91. When a cannon fires a cannonball, the cannon will recoil backward because the a. energy of the cannonball and cannon is conserved. b. momentum of the cannonball and cannon is conserved. c. energy of the cannon is greater than the energy of the cannonball. d. momentum of the cannon is greater than the energy of the cannonball.

20 Page A handball of mass 0.10 kg, traveling horizontally at 30 m/s, strikes a wall and rebounds at 24 m/s. What is the change in the momentum of the ball? a kgúm/s b. 1.2 kgúm/s c. 5.4 kgúm/s d. 72 kgúm/s 93. A machine gun, of mass 35.0 kg, fires 50.0-gram bullets, with a muzzle velocity of 750 m/s, at the rate of 300 rounds per minute. What is the average force exerted on the machine gun mount? a N b. 188 N c. 219 N d. 438 N 94. A fire hose is turned on the door of a burning building in order to knock the door down. This requires a force of 1000 N. If the hose delivers 40 kg per second, what is the minimum velocity of the stream needed, assuming the water doesn't bounce back? a. 15 m/s b. 20 m/s c. 25 m/s d. 30 m/s 95. Water runs out of a horizontal drainpipe at the rate of 120 kg per minute. It falls 3.20 m to the ground. Assuming the water doesn't splash up, what average force does it exert on the ground? a N b N c N d N 96. A rubber ball with a speed of 5.0 m/s collides head-on elastically with an identical ball at rest. What is the speed of the initially stopped ball after the collision? a. zero b. 1.0 m/s c. 2.5 m/s d. 5.0 m/s

21 Page A railroad car, of mass 200 kg, rolls with negligible friction on a horizontal track with a speed of 10 m/s. A 70-kg stunt man drops straight down a distance of 4.0 m, and lands in the car. How fast will the car be moving after this happens? a. 2.8 m/s b. 4.7 m/s c. 7.4 m/s d. 10 m/s 98. A car of mass m, traveling with a velocity v, strikes a parked station wagon, whose mass is 2m. The bumpers lock together in this head-on inelastic collision. What fraction of the initial kinetic energy is lost in this collision? a. 1/2 b. 1/3 c. 1/4 d. 2/3 99. A 2.0-kg mass moving to the east at a speed of 4.0 m/s collides head-on in a perfectly inelastic collision with a stationary 2.0-kg mass. How much kinetic energy is lost during this collision? a. 16 J b. 4.0 J c. 8.0 J d. zero 100. A model rocket sits on the launch pad and its fuel is ignited, blasting the rocket upward. What happens to the center of mass of the rocket-fuel system? a. It goes up. b. It is stationary. c. It follows the path of the rocket. d. It follows the path of the fuel.

22 Page 1 1. d 2. a 3. c 4. d 5. c 6. c 7. a 8. d 9. b 10. a 11. b 12. a 13. b 14. c 15. b 16. a 17. c 18. b 19. c 20. c 21. a 22. b 23. b 24. a 25. d 26. a 27. a 28. a 29. a 30. c 31. a 32. a 33. b 34. d 35. d 36. b 37. c 38. a 39. b 40. c 41. b 42. d 43. c 44. c 45. b 46. b 47. d 48. b 49. a 50. a 51. c 52. d 53. b 54. c

23 Page c 56. c 57. a 58. c 59. b 60. c 61. d 62. b 63. c 64. a 65. b 66. b 67. c 68. c 69. d 70. c 71. b 72. c 73. d 74. d 75. c 76. c 77. b 78. c 79. b 80. d 81. c 82. a 83. c 84. c 85. d 86. d 87. b 88. b 89. c 90. a 91. b 92. c 93. b 94. c 95. c 96. d 97. c 98. d 99. c 100. b