Choose the alternative that best answers the question and record your answer on the Scantron sheet provided 1. A ball of putty is thrown at a wall and sticks to its surface. Which of the following quantities is conserved in this situation? a. momentum b. inertia c. vis viva d. kinetic energy Use the following information for the next question Linear Accelerator The following is a simplification of what takes place when charged particles are accelerated and collisions take place. To acccelerate alpha particles, charged parallel plates may be used. The magnitude of the electric field between two charged parallel plates at a fixed distance d apart can be calculated for different distances x from the positive plate. In the collision area, the incoming alpha particles moving at 8.07 x 10 6 m/s collide with other alpha particles that are at rest Assume that each collision involves two alpha particles in an inelastic collision that form a new 8 4 Be (beryllium) nucleus. 2. What is the final momentum of the new 8 Be nucleus? 4 a. 1.07 x 10-19 kg. m/s b. 5.37 x 10-20 kg. m/s c. 2.68 x 10-20 kg. m/s d. 1.35 x 10-20 kg. m/s 3. Which of the following best represents the momentum of a small car travelling at a city speed limit? a. 1 000 kg. m/s b. 10 000 kg. m/s c. 100 000 kg. m/s d. 1 000 000 kg. m/s 4. A clerk working at a local food store is asked to retrieve the empty shopping carts left outside by shoppers. Each cart has a mass of 20.0 kg. The clerk places 8 carts, which are locked together, close to the entrance on a slight incline. The clerk gathers another 12 carts and pushes them toward the store entrance. Meanwhile, the first 8 carts roll toward the 12 carts with a speed of 2.30 m/s When the carts collide, they all come to a complete stop. At what speed were the 12 carts moving just before impact? a. 2.88 x 10-2 m/s b. 2.90 x 10-1 m/s c. 1.53 m/s d. 3.45 m/s
5. A single stationary railway car is bumped by a five-car train moving at 9.3 km/h. The six cars move off together after the collision. Assuming that the masses of all the railway cars are the same, then the speed of the new six-car train immediately after impact is: a. 7.8 km/h b. 8.5 km/h c. 9.3 km/h d. 11 km/h 6. Which set of conditions is true in all inelastic collisions? Momentum Kinetic Energy Total Energy Momentum Kinetic Energy Total Energy a. Conserved Conserved Conserved b. Conserved Not conserved Conserved c. Not conserved Not conserved Conserved d. Not conserved Conserved Not conserved 7. A 10 kg object traveling at 5.0 m/s north collides with and sticks to a 4.0 kg object travelling at 7.0 m/s south. Their common velocity after the collision is: a. 1.6 m/s N b. 22 m/s N c. 5.6 m/s S d. 64 m/s S 8. A car (mass 1000. kg) catches up with and runs into a motorcycle (mass 300. kg) both going the same direction as the car. The speed of the car is 100. km/h and the speed of the motorcycle is 75.0 km/h. After the collision they stick together. Assume there is no friction. The motorcycle's speed after the collision is: a. 40.6 km/h b. 56.3 km/h c. 81.3 km/h d. 94.2 km/h 9. A rubber and an aluminum bullet both have the same mass, speed and size. They are fired at a block of wood. Which is more likely to knock the block over? a. the rubber bullet b. the aluminum bullet c. both act the same d. neither would knock it over 10. The diagram shows a collision between a 4.0 kg toy car and a stationary 8.0 kg toy truck. After the collision, the car bounces back at 1.0 m/s while the truck goes forward at 2.0 m/s. Based on these values, are momentum and kinetic energy conserved? Momentum Kinetic Energy Momentum Kinetic Energy a. Conserved Conserved b. Conserved Not Conserved c. Not Conserved Conserved d. Not Conserved Not Conserved 11. A 1.2 kg ball moving due east at 40 m/s strikes a stationary 6.0 kg object. The 1.2 kg ball rebounds to the west at 25 m/s. What is the speed of the 6.0 kg object after the collision? a. 3.0 m/s b. 13 m/s c. 15 m/s d. 65 m/s
12. A 47.0 g golf ball is hit with an initial velocity of 70.0 m/s at an angle of 30.0 up from the horizontal. The vertical component of the ball's momentum is: a. 1.65 kg m/s b. 2.85 kg m/s c. 3.29 kg m/s d. 6.58 kg m/s 13. Use the work-energy theorem to find the force required to accelerate an electron (m = 9.11 x 10-31 kg) from rest to a speed of 1.50 x 10 7 m/s in a distance of 0.0125 m. a. 8.20 x 10-15 N b. 5.47 x 10-22 N c. 8.20 x 10-17 N d. 1.64 x 10-14 N e. 3.56 x 10-19 N 14. The initial velocity of a 4.0 kg box is 11 m/s, due west. After the box slides 4.0 m horizontally, its speed is 1.5 m/s. Determine the magnitude and the direction of the non-conservative force acting on the box as it slides. a. 42 N, due west b. 120 N, due east c. 31 N, due east d. 59 N, due east e. 83 N, due west 15. An object moving south collides with an object moving west on a low-friction surface. On impact, the objects lock together and move off at 45º to each object's original direction of motion. Before the collision of the two objects, the quantity that was the same for each was their a. masses b. velocities c. momentum d. kinetic energies 16. A 2.0 kg puck travelling due east at 2.5 m/s collides with a 1.0 kg puck travelling due south at 3.0m/s. They stick together on impact. What is the resultant direction of the combined pucks? a. 31 S of E b. 40 S of E c. 50 S of E d. 59 S of E 17. A 900 kg car travelling at 12 m/s due east collides with a 600 kg car travelling at 24 m/s due north. As a result of the collision, the two cars lock together and move in what final direction? a. 45 o N of E b. 53 o N of E c. 63 o N of E d. 69 o N of E Use the following information to answer the next question: A stationary bomb exploded in a street in the centre of the city. The three pieces of debris from the bomb, each of approximately the same mass, flew off horizontally in different directions. Analysis revealed that one piece moved east at 20.0 m/s, and a second piece moved southeast at 30.0 m/s. 18. The third piece of debris was difficult to locate Where should investigators look for the third piece? a. 27 o W of N b. 27 o N of W c. 22.5 o S of W d. 22.5 o N of E
19. A small explosive device sliding to the right breaks into two pieces. The momentum of fragment 1 after the explosion is 23 kg m/s. What is the momentum of fragment 2 after the explosion? a. 22 kg m/s b. 23 kg m/s c. 30 kg m/s d. 32 kg m/s 20. The physical quantity that can have the same unit as impulse is: a. force b. work c. power d. momentum 21. Which of the following would not decrease the force experienced in a fall? a. land on a surface supported by springs b. bend one's knees when landing from a height c. land on a haystack d. land on a one's back with arms and legs extended 22. In order to stop two sliding objects, the greater impulse must be given to the one having the greater: a. mass. b. speed. c. velocity. d. momentum. 23. A ball is thrown at 15 m/s towards various barriers. In which case does the ball experience the greatest impulse? a. The ball hits a wall and rebounds at 2.0 m/s. b. The ball hits a wall and rebounds at 7.0 m/s. c. The ball hits a wall, sticks to it and stops moving. d. The ball breaks a window and continues moving at 10 m/s in the same direction. 24. Which of the following are equivalent units for change in momentum? a. kg. m/s 2 b. N. s c. kg. s/m d. N/s 25. A 1.0 kg ball of putty hits a wall perpendicularly with a speed of 5.0 m/s and sticks to it. The ball undergoes a change in momentum of a. -1.0 kg m/s b. -5.0 kg m/s c. -10.0 kg m/s d. 0 kg m/s 26. A 0.080 kg tennis ball travelling east at 15 m/s is struck by a tennis racquet, giving it a velocity of 25 m/s, west. What are the magnitude and direction of the impulse given to the ball? MAGNITUDE DIRECTION MAGNITUDE DIRECTION a. 0.80 N. s Eastward b. 0.80 N. s Westward c. 3.2 N. s Eastward d. 3.2 N. s Westward
27. A 0.30 kg ball rolls off a horizontal surface as shown in the diagram. What is the magnitude of the impulse given to the ball by gravity during the 0.90 s it takes the ball to fall to the ground? a. 1.5 N. s b. 2.6 N. s c. 3.0 N. s d. 41 N. s 28. Which expression is equal to the net force on an object? a. Δρ b. W c. mδv d. ΔE Δt Δt 29. A 0.15 kg ball travelling at 25 m/s strikes a wall and bounces back in the opposite direction at 15 m/s. The ball is in contact with the wall for 0.030 seconds. What average force does the wall exert on the ball? a. 25 N b. 50 N c. 1.0 x 10 2 N d. 2.0 x 10 2 N 30. A 160 kg space probe is moving in the positive x direction at 18 km/s when it encounters a time dependent force directed in the negative x direction. The force is as follows: Determine the final speed of the space probe. a. 8.6 km/s b. 5.3 km/s c. 11 km/s d. 16 km/s e. 23 km/s 31. For vehicles that become stuck in snow or mud, a chain of fixed length, or a nylon tow rope that stretches, is often used to recover the stuck vehicle. When the stuck vehicle is being pulled, its change in momentum will a. increase over a longer time when the tow rope is used b. decrease over a shorter time when the chain is used c. increase over a longer time when the chain is used d. decrease over a longer time when the tow rope is used 32. A net force of 20 N acts for 1.5 s on a 4.0 kg object initially at rest. What is the final kinetic energy of the object? a. 30 J b. 1.1 x 10 2 J c. 2.3 x 10 2 J d. 4.4 x 10 2 J
Use the following information for the next five questions Air bags are designed to deploy when a car, moving at a minimum speed of 18 km/h, comes to a crashing stop. The impact sensor, also moving at 18 km/h, consists of a small steel ball of 0.050 kg, which is held in position by a magnet, as shown. On impact, the ball breaks free in 1.00 x 10-3 s and slides within a cylinder. The ball makes contact with two electrodes at the end of the cylinder, thus activating the air bag. 33. What is the magnitude of the force required to break away from the magnet? a. 2.5 x 10 5 N b. 1.3 x 10 5 N c. 2.5 x 10 2 N d. 1.3 x 10 2 N 34. If the car was moving at 18 km/h, the maximum speed of the ball immediately after impact would be: a. 62 m/s b. 18 m/s c. 5.0 m/s d. 0 m/s 35. When the ball makes contact with the electrodes at the end of the cylinder, the ball behaves like a: a. circuit b. switch c. resistance d. energy source 36. If the car was initially moving 18 km/h, the driver had a mass of 70 kg, and the air bag stopped him in 0.10 s, the magnitude of the force acting on the driver during the deceleration would be: a. 1.3 x 10 4 N b. 3.5 x 10 3 N c. 1.3 x 10 3 N d. 3.5 x 10 2 N 37. The entire process, from impact to air bag inflation, takes less than 3.0 x 10-3 s. During this same time, how far forward would a passenger who was not wearing a seat belt move? a. 1.5 x 10-2 m b. 1.8 x 10-2 m c. 5.0 m d. 0 m Two space capsules are initially at rest in deep space with a compressed spring between them. Capsule P has twice the mass of capsule Q. The capsules are forced apart when the spring is released. The magnitude of the impulse acting on capsule P is 10 Ns. 38. The magnitude of the impulse acting on capsule Q is: a. 2.0 N. s b. 5.0 N. s c. 10 N. s d. 20 N. s 39. The total momentum in kg. m/s of the capsules after they have separated is: a. 0 b. 5.0 c. 10 d. 20
40. The graph shows the forces experienced by an astronaut during a rocket launch into a stable orbit. In which time interval was the acceleration of the rocket the greatest? a. S-T b. T-U c. U-V d. V-W 41. Which of the following represents a unit of power? a. kilowatt. hour b. Newton. metre c. kg. m/s d. kg. m 2 /s 3 42. The power of a motor can be measured in: a. N. s b. J c. W. s d. 43. A shell is fired from a cannon and explodes in mid-air. During the explosion its total a. momentum increases b. momentum decreases c. kinetic energy increases d. kinetic energy decreases 44. Which of the following describes kinetic energy and momentum before and after a perfectly elastic collision? KINETIC ENERGY MOMENTUM KINETIC ENERGY MOMENTUM a. Not Conserved Not Conserved b. Not Conserved Conserved c. Conserved Not Conserved d. Conserved Conserved 45. A stationary object of mass m is on the surface of a planet of mass M and radius r. Which of the following gives the force required to move the object infinitely far away? a. GMm b. c. d. F g = F g = GMm F g = GMm r r 2r
46. A 120 kg astronaut stands on the surface of an asteroid of radius 600 m. The astronaut leaves the surface with 15 J of kinetic energy and reaches a maximum height of 300 m above the surface. What is the mass of the asteroid? a. 5.6 x 10 11 kg b. 2.2 x 10 12 kg c. 3.4 x 10 12 kg d. 5.1 x 10 12 kg 47. Relative to zero at infinity, what is the gravitational potential energy of a 7.2 x 10 2 kg satellite that is at a distance of 3.4 x 10 7 m from earth's centre? a. -2.4 x 10 11 J b. -8.4 x 10 9 J c. 8.4 x 10 9 J d. 2.4 x 10 11 J 48. The graph shows the relationship between the force applied and the distance moved for a 3.5 kg object on a frictionless horizontal surface. If the object was initially at rest, what is its kinetic energy after travelling 8.0 m? a. 2.0 J b. 32 J c. 64 J d. 1.3 x 10 2 J 49. A cyclist travelling at 10 m s applies her brakes and stops in 25 m. The graph shows the magnitude of the braking force versus the distance travelled. What is the total mass of bike and cyclist? a. 20 kg b. 40 kg c. 64 kg d. 80 kg
50. Two blocks are initially held together on a frictionless surface as shown in the diagram. When the string is cut, the blocks fly apart as shown. What work was done on the blocks by the spring? a. 0 J b. 0.29 J c. 0.43 J d. 0.58 J