CHAPTER 6 TEST Directions: Show work on problems. Choose correct answer when available and place next to the question number. 1. What is inertia? A. the amount of matter in an object B. the force of gravity on an object C. the amount of force acting on each kilogram of mass D. that property that causes an object to resist changes in its state of motion 2.If you stand on a bus as it is slowing down, what does your body's inertia cause you to do? A. Brace yourself to keep from falling backwards. B. Brace yourself to keep from falling forwards. C. Brace yourself to keep from falling to the side. D. nothing 3. What is the relationship between the amount of inertia of an object and the object's mass? A. The amount of inertia equals an object's mass. B. The amount of inertia depends inversely on an object's mass. C. The amount of inertia depends directly on an object's mass. D. The amount of inertia depends directly on the square of an object's mass. 4. Which of the following is NOT associated with Isaac Newton? A. Mechanica C. F = ma B. The Law of Inertia D. Principia Mathematica 5. Which of the following is a statement of Newton's First Law of Motion? A. If no unbalanced force acts on an object, the object accelerates in the direction of the single greatest force acting on the object. B. If no net force acts on an object, the object maintains its state of rest or its constant speed in a straight line. C. Acceleration varies directly with the unbalanced force. D. For every action force, there exists a reaction force that is equal in magnitude but opposite in direction. 6. Which of the following is a statement of Newton's Second Law of Motion? A. If an unbalanced force acts on an object, the object accelerates in the direction of the force. B. If no net force acts on an object, it maintains its state of rest or its constant speed in a straight line. C. For every action force, there exists a reaction force that is equal in magnitude but opposite in direction. D. When no external, unbalanced force acts on an object, its velocity remains constant. 7.Which of the following is a statement of Newton's Third Law of Motion? A. If an unbalanced force acts on an object, the object accelerates in the direction of the force. B. If no net force acts on an object, it maintains its state of rest or its constant speed in a straight line. C. For every action force, there exists a reaction force that is equal in magnitude but opposite in direction.
D. When no external, unbalanced force acts on an object, its velocity remains constant. 8. Construct a free body diagram of the following forces. What are the magnitude and the direction of the unbalanced force? (1) 3.0 N[N] (5) 3.5 N[S] (2) 2.0 N[E] (6) 3.5 N[W] (3) 4.5 N[E] (7) 3.0 N[W] (4) 2.5 N[S] A. 2.0 N[N] B. 3.0 N[S] C. 2.5 N[E] D. 1.5 N[W] 9. Construct a free body diagram of the following forces. What are the magnitude and the direction of the unbalanced force? (1) 175 N[N] (5) 115 N[S] (2) 25 N[N] (6) 85 N[S] (3) 350 N[E] (7) 430 N[W] (4) 225 N[E] (8) 145 N[W] A. 75 N[N] B. 175 N[E] C. 0 N D. 285 N[W] 10. Having run out of gas in their car, a group of students are pushing the car at a constant speed of 2.2 m/s. Together their applied force is 4000 N in the direction of the car's motion. Which of the 1following is true about the force of friction on the tires of the car? A. It is equal to 4000 N plus the force of gravity on the car. B. It is greater than 4000 N. C. It is less than 4000 N. D. It is equal to 4000 N. 11. How is the acceleration of an object related to the mass of the object and the net force acting on the object? A. Acceleration varies directly with both the unbalanced force and the mass. B. Acceleration varies inversely with both the unbalanced force and the mass. C. Acceleration varies directly with the unbalanced force and inversely with the mass. D. Acceleration varies inversely with the unbalanced force and directly with the mass. 12.What is the acceleration of a 65 kg water-skier acted on by a net force of 169 N[E]? A. 0.38 m/s[e] C. 1.1 x 10 m/s[e] B. 3.8 m/s[e] D. 2.6 m/s[e] 13. What is the net force needed to provide an acceleration of -21.6 km/h/s to a 1500 kg car and bring it to a stop? A. 9000 N B. -9000 N C. -1494 N D. -250 N 14. A pitcher applies an average force of 26 N while accelerating a ball from rest to 36 m/s through a distance of 2.5 m. Calculate the mass of the ball. A. 0.10 kg B. 5.16 kg C. 0.72 kg D. 3.46 kg USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT 4 16. Truck and tractor pulling is a growing motor sport in many areas of the country. The objective is to see who can pull a weighted "sled" the farthest. A "full pull" may consist of pulling the sled 90 m. A
5000 horsepower tractor can apply a force of 5.0 x 10^5 N to uniformly accelerate over a 90 m course in about 12 s. If the tractor weighs 6.0 x 10^4N, how much force is it exerting on the sled that it is pulling if it is using all the force its motor can provide? A. 5.4 x 10^5 N C. 3.0 x 10^10 N B. 4.9 x 10^5 N D. 8.3 x 10^10 N 17. If the coefficient of friction between the tires of the sled and the track is 0.8979, what is the total weight of the sled? A. 3.9 x 10^5 N B. 4.8 x 10^5 N C. 5.6 x 10^4 N D. 5.0 x 10^4 N 18. What is the mass of the sled? A. 3.9 x 10^5 kg C. 5.6 x 10^4 kg B. 4.9 x 10^5 kg D. 4.9 x 10^4 kg 19. If, at a constant speed, the force that the tractor exerts on the sled is equal to the force that the sled pulls on the tractor, what force is moving the tractor and sled forward? A. the forward force of the tractor on the sled B. the backward force of the sled on the tractor C. the forward force of the ground pushing on the tractor's tires D. the backward force of the tractor's tires on the ground 20. If the tractor driver completes a "full pull" by pulling the sled the full 90 m and the driver completes the pull in 12 s, what is the driver's average velocity? A. 75 m/s B. 7.5 m/s C. 1080 m/s D. 108 m/s USE THE FOLLOWING SITUATION TO ANSWER THIS QUESTION AND THE NEXT 2 A snowmobile is pulling two cross-country skiers across snow with a force of 405 N[E]. The skier closest to the snowmobile, skier A, has a mass of 75 kg; the other skier, skier B, has a mass of 60 kg. A rope connects the first skier to the snowmobile. A second rope connects the two skiers. 21. What is the acceleration of the skiers? Ignore friction between the skiers and the snow. A. 3.0 m/s[w] B. 5.4 m/s[e] C. 5.4 m/s[w] D. 3.0 m/s[e] 22. What is the force exerted by skier A on skier B? Ignore friction. A. 180 N[E] B. 180 N[W] C. 225 N[E] D. 225 N[W] 23. What is the force exerted by skier B on skier A? Ignore friction. A. 180 N[E] B. 180 N[W] C. 225 N[E] D. 225 N[W] USE THE FOLLOWING SITUATION TO ANSWER THIS QUESTION AND THE NEXT 2 24. A dogsled team exerts a force of 845 N[N] on a sled and driver. The 75 kg driver is riding on the sled. Also, the sled and additional contents have a combined mass of 100 kg. Frictional resistance amounts to 600 N. If the team of dogs starts from rest and pulls for 12.0 s, what is the acceleration of the combination of sled, contents, and driver? A. 3.3 m/s[n] B. 3.3 m/s[s] C. 1.4 m/s[n] D. 1.4 m/s[s] 25. What is the velocity attained by the sled, contents, and driver in 12.0 s? A. 16.8 m/s[n] B. 16.8 m/s[s] C. 8.6 m/s[n] D. 8.6 m/s[s]
26. How far will the sled, contents and driver travel in 12.0 s? A. 8.4 m[n] B. 16.8 m[s] C. 202 m[s] D. 101 m[n] 27.What did Newton call momentum? A. impulse C. the quality of motion B. acceleration D. the quantity of motion 28. What is the equation for momentum? A. p = ma C. p = mv^2 B. p = mv D. p = Gm^2 29. What is momentum? A. Momentum is a scalar quantity whose magnitude is always the same as that of the object's velocity. B. Momentum is a scalar quantity whose magnitude is the same as the magnitude of the net force causing the momentum. C. Momentum is a vector quantity whose direction is always the same as that of the object's velocity. D. Momentum is a vector quantity whose direction is opposite to the direction of the net force causing the momentum. 30. What is the momentum of a 250 kg snowmobile moving at 34.6 km/h[n]? A. 2.4 x 10^3 kg m/s[n] C. 2.4 x 10^3 kg m/s[s] B. 2.6 x 10^10 kg m/s[n] D. 2.6 x 10^10 kg m/s[s] 31. What is impulse? A. a scalar quantity whose magnitude is always the same as that of the object's velocity B. a scalar quantity whose magnitude is the same as the magnitude of the net force causing the impulse C. a vector quantity whose direction is always opposite to that of the object's velocity D. a vector quantity whose direction is the same as the direction of 32. Which of the following applies to a passenger in an automobile who is protected by an air bag as opposed to one who is not protected by an air bag? A. The impulse of the protected passenger is less than the unprotected passenger's impulse. B. The impulse of the protected passenger is greater than the unprotected passenger's impulse. C. The impulse of the protected passenger is the same as the unprotected passenger's impulse. D. The impulse of the protected passenger is zero. USE THE ABOVE DIAGRAMS TO ANSWER THIS QUESTION AND THE NEXT 5 33. A pole vaulter has a mass of 50 kg. What net force upward must the pole exert in order to provide the pole vaulter with an upward acceleration of 2.5 m/s^2 A. 1200 N B. 196 N C. 125 N D. 20 N 34. What is the total upward force being exerted by the pole on the pole vaulter? A. 125 N B. 365 N C. 1200 N D. 615 N 35. The pole vaulter runs along an approach to a crossbar 5.5 m in height. As he plants the pole, his forward momentum bends the pole enough to accelerate him up to the crossbar. What impulse is exerted on the
pole if the pole is planted and bent in 0.400 s? A. 50.0 N s B. 200 N s C. 246 N s D. 310 N s 36. With what velocity did the pole vaulter run forward in order to exert the above impulse on the pole and bend it as he did? (Assume that the vaulter's final horizontal velocity is zero.) A. 1.0 m/s B. 4.0 m/s C. 6.2 m/s D. 4.9 m/s 37. Twenty-two points, plus triple-word-score, plus fifty points for using all my letters. Game's over. I'm outta here. completes his run and plants his pole, he begins his vertical takeoff. His initial vertical velocity is zero before beginning his swing upwards. If the vaulter's pole is 5.0 m in length and it accelerates him upwards at 2.5 m/s^2, how long does it take the pole vaulter to be swung to the top of his pole? A. 2.0 s B. 4.0 s C. 0.25 s D. 0.50 s 38. What velocity upwards was the pole vaulter moving as he reached the top of his pole? Again, his initial vertical velocity is zero. A. 10.0 m/s B. 5.0 m/s C. 0.6 m/s D. 1.3 m/s 39. What does the Law of Conservation of Momentum mean with respect to colliding objects? A. The total momentum before a collision is greater than the total momentum after the collision. B. The total momentum before a collision is less than the total momentum after the collision. C. The total momentum during a collision is equal to the sum of the total momentum before the collision plus the total momentum after the collision. D. The total momentum before a collision is the same as the total momentum after the collision. 40. A 2000 kg mini-van runs into the rear of an 800 kg compact car that was at rest. They hook together during collision and move off together at 7.50 m/s in the same direction that the van was heading. Ignoring friction with the ground, what was the initial speed of the mini-van? A. 7.50 m/s B. 4.50 m/s C. 10.5 m/s D. -4.50 m/s USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT 3 41. A space shuttle transportation system, when fully loaded and fully fuelled, has a mass of approximately 1.80 x 10^6 kg. What is the downward force of gravity on the system at blast-off? A. 1.80 x 10^6 N C. 1.80 x 10^7 N B. 1.76 x 10^7 N D. 1.76 x 10^6 N 42.The space shuttle's solid rocket boosters plus the shuttle's own liquid fuel engines provide an upward thrust of 2.70 x 107 N. What is the net force on the shuttle system at blast-off? A. 1.80 x 10^6 N C. 9.40 x 10^6 N C. 2.40 x 10^7 N D. 2.58 x 10^7 N 43. What is the acceleration of the shuttle as it is leaving the launching platform? A. 5.20 m/s^2 B. 15.0 m/s^2 C. 0.19 m/s^2 D. 16.9 m/s^2 44. Upon re-entering Earth's atmosphere, the space shuttle has a mass of approximately 6.7 x 10^4 Kg and enters at about 2.5 x 10^4 km/h.
What is the magnitude of the shuttle's momentum upon re-entry? A. 4.7 x 10^4 kg m/s C. 1.7 x 10^9 Kg m/s B. 1.7 x 10^11 Kg m/s D. 4.6 x 10^8 Kg m/s USE THE ABOVE GRAPH TO ANSWER THIS QUESTION AND THE NEXT 3 45. The graph represents two instances of a 50 kg student travelling in a car at about 90 km/h and then crashing into a wall. What is the impulse when the student comes to a sudden stop in 0.05 s with a force of 25 000 N? A. 2.5 x 10^5 N s B. 5.0 x 10^5 N s C. 2500 N s D. 1250 N s 46. What is the impulse when an air bag reduces the force to 1250 N by extending the length of time over which the total force is applied to 1.0 s? A. 2.5 x 10^5 N s B. 5.0 x 10^5 N s C. 2500 N s D. 1250 N s 47.What is the momentum of the 50 kg student travelling at 90 km/h? A. 2.5 x 10^5 kg m/s C. 2500 kg m/s B. 5.0 x 10^5 kg m/s D. 1250 kg m/s 48. How does putting air bags in cars save lives in collisions? A. An air bag reduces the momentum of a person's body. B. An air bag reduces the force on a person's body. C. An air bag reduces the impulse of a person's body. D. An air bag reduces the time the force on a person's body is applied. USE THE ABOVE DIAGRAMS TO ANSWER THIS QUESTION AND THE NEXT 5 49.A pitcher releases a 0.15 kg baseball at a velocity of +36 m/s. What is the momentum of the baseball when it is released? A. 5.4 kg m/s B. 54.0 kg m/s C. 2.4 kg m/s D. 240 kg m/s 50.What impulse does the pitcher deliver to the baseball? A. 5.4 Nùs B. 54.0 Nùs C. 2.4 Nùs D. 240 Nùs 51. The batter hits the ball horizontally back to the pitcher at -60 m/s. Assuming that the ball does not lose speed on its way to the batter, what impulse does the bat deliver to the ball? A. -9.0 kg m/s B. -14.4 kg m/s C. -3.6 kg m/s D. -640 kg m/s 52. If the bat and ball are in contact for 8.0 x 10^-4 s, what is the average force the bat exerts on the ball? A. 1.8 x 10^4 N C. -7.2 x 10^-3 N B. 1.2 x 10^-2 N D. -1.8 x 10^4 N 53. The ball is in contact with the bat for 8.0 x 10^-4 s. What acceleration does the ball experience during that time? A. 1.2 x 10^5 m/s^2 C. -1.2 x 10^5 m/s^2 B. 5.3 x 10^-3 m/s^2 D. -4.8 x 10^-2 m/s^2 54. The pitcher provides the baseball with a velocity of +36 m/s by applying a force of 4.5 N for 1.2 s. What velocity could he have given the ball if he had reached back farther and applied the same force for 1.4 s? A. +38 m/s B. +40 m/s C. +42 m/s D. +44 m/s 55. When a car stops suddenly, according to Newton's First Law of Motion, an unbelted rider will continue to move
forwards as a result of inertia and will collide with the car's dashboard. Using one of Newton's laws of motion, explain the importance of wearing a seat belt while riding in a car. 56. What average force will stop a 5700 kg truck in 2.0 s if it is moving at 91 km/h? 57. What is the impulse given to an incoming baseball by a batter if the bat and ball are in contact for 0.0007 s and the bat exerts an average force of -1.4 x 10^4 N? 58. The horse exerts a net force on the cart. The force of the cart on the horse only affects the horse's motion, not the cart's motion. According to Newton's Third Law of Motion, when a horse exerts a force on a cart, the cart exerts an equal force in the opposite direction. According to Newton's First Law of Motion, when no unbalanced force acts on an object, it remains at rest. How, then, can a horse pull a cart forwards? Yes, but since there is such a large difference in the mass of a bullet and the mass of a truck, the velocity of the bullet would have to be great enough for 59. Is it possible for a bullet and a truck to have the same momentum? Explain. The sum total of the mass of the fuel particles times the velocity of the fuel particles ejected downward equals the mass of the rocket times the velocity of the rocket upward. 60. How does the Law of Conservation of Momentum account for rocket propulsion? Fire your on-board rockets in the direction in which you are moving. The momentum of your spacecraft would be reduced by an amount equal to the momentum of the high-velocity fuel particles. 61. If you are speeding along in space, how would you slow your spacecraft down? USE THE FOLLOWING KEY TO ANSWER THIS QUESTION AND THE NEXT 4 KEY: A. acceleration
B. kinematics C. inertia D. action-reaction E. dynamics 62. Which branch of physics deals with the description of motion? 63. Which branch of physics deals with the causes of motion? 64. Which property causes a body to resist changes in its state of motion? 65. What varies directly with the unbalanced force on an object and inversely with its mass? 66. What exemplifies the idea that forces exist in pairs? USE THE FOLLOWING KEY TO ANSWER THIS QUESTION AND THE NEXT 4 KEY: A. Newton's First Law of Motion B. Newton's Second Law of Motion C. Newton's Third Law of Motion D. Galileo's Law of Motion When stepping from a canoe onto a dock, the canoe moves backwards in the water as you step forwards. Which law explains this motion? 67. You are riding in a car, tossing a tennis ball up and down in your hand. Which law explains this motion? 68. Which law of motion explains walking, driving, swimming, flying, and rocketry. 69. Which law of motion explains the acceleration of objects? 70. Which law of motion explains the importance of using seat belts when driving or riding in cars? USE THE FOLLOWING KEY AND INFORMATION TO ANSWER THIS QUESTION AND THE NEXT 2 KEY: A. mdsvds B. morv'or C. morvor D. mdsv'ds 71. During a football game, a defensive safety (ds) and an offensive receiver (or) both chase after a long pass from different areas of the field. They collide and bounce off each other in mid-air. Which expression identifies the momentum of the offensive receiver before the collision?
72. Which expression identifies the momentum of the offensive receiver after the collision. 73. Which expression identifies the momentum of the defensive safety after the collision. 74. How does an object's acceleration change when the unbalanced force acting on it is doubled? A. The object's acceleration becomes one-half. B. The object's acceleration doubles. C. The object's acceleration remains the same. C. The object's acceleration quadruples. 75.If a 2.0 N force accelerates one cart at 0.5 m/s2, what acceleration will a 6.0 N force produce on a stack of three carts? A. 1.0 m/s^2 B. 1.5 m/s^2 C. 3.0 m/s^2 D. 0.5 m/s^2 76. As the trigger of a spring-loaded cart is released, four stacked carts repel a single cart. The single cart travels 64 cm. How far do the four stacked carts travel? A. 16 cm B. 32 cm C. 48 cm D. 64 cm