1. | The law of conservation of momentum applies to a system of colliding objects only if: |
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2. | Block A, with a mass of 2.0 kg, moves along the x axis with a velocity of 5.0 m/s in the positive x direction. It suﬀers an elastic collision with block B, initially at rest, and the blocks leave the collision along the x axis. If B is much more massive than A, the speed of A after the collision is: |
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3. | The physical quantity “impulse” has the same dimensions as that of: |
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4. | A sinusoidal force with a given amplitude is applied to an oscillator. At resonance the amplitude of the oscillation is limited by: |
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5. | A particle is in simple harmonic motion with period T. At time t = 0 it is at the equilibrium point. Of the following times, at which time is it furthest from the equilibrium point? |
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6. | Force: |
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7. | At the same instant that a 0.50-kg ball is dropped from 25 m above Earth, a second ball, with a mass of 0.25 kg, is thrown straight upward from Earth’s surface with an initial speed of 15 m/s. They move along nearby lines and pass without colliding. At the end of 2.0 s the magnitude of the acceleration of the center of mass of the two-ball system is: |
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8. | In simple harmonic motion, the magnitude of the acceleration is greatest when: |
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9. | A 0.25-kg block oscillates on the end of the spring with a spring constant of 200 N/m. If the system has an energy of 6.0 J, then the maximum speed of the block is: |
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10. | An object attached to one end of a spring makes 20 complete oscillations in 10 s. Its period is: |
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11. | If the total momentum of a system is changing: |
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12. | A meter stick is pivoted at a point a distance a from its center and swings as a physical pendulum. Of the following values for a, which results in the shortest period of oscillation? |
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13. | A 640-N hunter gets a rope around a 3200-N polar bear. They are stationary, 20 m apart, on frictionless level ice. When the hunter pulls the polar bear to him, the polar bear will move: |
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14. | A student’s life was saved in an automobile accident because an airbag expanded in front of his head. If the car had not been equipped with an airbag, the windshield would have stopped the motion of his head in a much shorter time. Compared to the windshield, the airbag: |
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15. | It is impossible for two particles, each executing simple harmonic motion, to remain in phase with each other if they have diﬀerent: |
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16. | At the same instant that a 0.50-kg ball is dropped from 25 m above Earth, a second ball, with a mass of 0.25 kg, is thrown straight upward from Earth’s surface with an initial speed of 15 m/s. They move along nearby lines and pass each other without colliding. At the end of 2.0 s the height above Earth’s surface of the center of mass of the two-ball system is: |
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17. | Five particles undergo damped harmonic motion. Values for the spring constant k, the damping constant b, and the mass m are given below. Which leads to the smallest rate of loss of mechanical energy? |
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18. | A particle moves in simple harmonic motion according to x = 2 cos(50t), where x is in meters and t is in seconds. Its maximum velocity in m/s is: |
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19. | A cart loaded with sand slides forward along a horizontal frictionless track. As the cart moves, sand trickles out at a constant rate through a hole in the back of the cart. The acceleration of the cart is: |
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20. | Three physical pendulums, with masses m1, m2 = 2m1, and m3 = 3m1, have the same shape and size and are suspended at the same point. Rank them according to their periods, from shortest to longest. |
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21. | The thrust of a rocket is: |
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22. | The center of mass of a uniform disk of radius R is located: |
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23. | An oscillatory motion must be simple harmonic if: |
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24. | A simple pendulum consists of a small ball tied to a string and set in oscillation. As the pendulum swings the tension force of the string is: |
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25. | In simple harmonic motion, the magnitude of the acceleration is: |
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26. | An object on the end of a spring is set into oscillation by giving it an initial velocity while it is at its equilibrium position. In the ﬁrst trial the initial velocity is v0 and in the second it is 4v0. In the second trial: |
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27. | A 3.00-g bullet traveling horizontally at 400 m/s hits a 3.00-kg wooden block, which is initially at rest on a smooth horizontal table. The bullet buries itself in the block without passing through. The speed of the block after the collision is: |
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28. | Block A, with a mass of 4 kg, is moving with a speed of 2.0 m/s while block B, with a mass of 8 kg, is moving in the opposite direction with a speed of 3 m/s. The center of mass of the two block-system is moving with a velocity of: |
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29. | Two objects, X and Y, are held at rest on a horizontal frictionless surface and a spring is compressed between them. The mass of X is 2/5 times the mass of Y. Immediately after the spring is released, X has a kinetic energy of 50 J and Y has a kinetic energy of: |
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30. | When you step on the accelerator to increase the speed of your car, the force that accelerates the car is: |
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31. | A certain spring elongates 9.0 mm when it is suspended vertically and a block of mass M is hung on it. The natural angular frequency of this block-spring system: |
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32. | For an oscillator subjected to a damping force proportional to its velocity: |
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33. | Whenever an object strikes a stationary object of equal mass: |
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34. | A block on a spring is subjected to a damping force that is proportional to its velocity and to an applied sinusoidal force. The energy dissipated by damping is supplied by: |
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35. | For a completely inelastic two-body collision the kinetic energy retained by the objects is the same as: |
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36. | Bullets from two revolvers are ﬁred with the same velocity. The bullet from gun #1 is twice as heavy as the bullet from gun #2. Gun #1 weighs three times as much as gun #2. The ratio of the momentum imparted to gun #1 to that imparted to gun #2 is: |
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37. | At the same instant that a 0.50-kg ball is dropped from 25 m above Earth, a second ball, with a mass of 0.25 kg, is thrown straight upward from Earth’s surface with an initial speed of 15 m/s. They move along nearby lines and pass without colliding. At the end of 2.0 s the velocity of the center of mass of the two-ball system is: |
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38. | A 2.0-kg block is attached to one end of a spring with a spring constant of 100 N/m and a 4.0-kg block is attached to the other end. The blocks are placed on a horizontal frictionless surface and set into motion. At one instant the 2.0-kg block is observed to be traveling to the right with a speed of 0.50 m/s and the 4.0-kg block is observed to be traveling to the left with a speed of 0.30 m/s. Since the only forces on the blocks are the force of gravity, the normal force of the surface, and the force of the spring, we conclude that: |
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39. | A 10-kg block of ice is at rest on a frictionless horizontal surface. A 1.0-N force is applied in an easterly direction for 1.0 s. During this time interval, the block: |
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40. | A 0.20-kg object attached to a spring whose spring constant is 500 N/m executes simple harmonic motion. If its maximum speed is 5.0 m/s, the amplitude of its oscillation is: |
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41. | A particle moves back and forth along the x axis from x = −xm to x = +xm, in simple harmonic motion with period T. At time t = 0 it is at x = +xm. When t = 0.75T: |
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