1.An 8-kg block moving to the right collides with and sticks to a 6-kg block moving to the left. Which statement best describes the motion of the combined blocks immediately after the collision?

They should be moving to the right. They should be moving to the left. They are at rest. It cannot be determined without knowing the speeds before the collision.

2. Physics students are studying momentum. Using a 3-kg box, they record the applied force at several equally spaced positions as the box is pushed from rest across a horizontal surface. The students create the graph shown below with force on the y-axis in newtons (N) and position on the x-axis in meters (m). Friction between the box and the surface is negligible.

https://cdn.flvs.net/assessment_images/educator_apphysics_v23/06_10_pt1_31_flvs.jpg

According to the data, the change in momentum of the box is most nearly

3 kg m/s 14 kg m/s 21 kg m/s 72 kg m/s

3. A 2.54-kg bucket hangs on a rope wrapped around a pulley of mass 10.07 kg and radius 56.0 cm. This pulley is frictionless in its axle and has the shape of a solid uniform disk. After the bucket has been released, what is the angular acceleration of the pulley?

5.65 rad/s² 3.16 rad/s² 1.82 rad/s² 0.79 rad/s²

^4. The figure below details the top view of a uniform, rigid beam of length 2.0 m. The beam lies on a horizontal surface, and one end pivots about an axis that is perpendicular to the beam and along the horizontal plane. A 50 N force is applied to the beam at its midpoint at an angle of 32. A second force F is applied to the nonpivoting end of the beam so that the beam remains at rest.

https://cdn.flvs.net/assessment_images/educator_apphysics_v23/06_10_pt1_50_flvs.jpg

What is the approximate magnitude of the torque produced by force F?

26.0 N m 42.0 N m 52.0 N m 75.0 N m

5. A 0.250-kg stone is attached to an ideal spring and undergoes simple harmonic oscillations with a period of 0.640 s. What is the force constant (spring constant) of the spring?

2.45 N/m 12.1 N/m 24.1 N/m 0.102 N/m

6. A square container of mass 1.0 kg slides on a horizontal, frictionless surface with a velocity of 10.0 m/s to the right and collides with a block of mass 4.0 kg at rest. As a result of the collision the container moves to the left at 4.2 m/s, and the block moves to the right at a velocity of 3.55 m/s to the right. Which of the following statements correctly identifies the type of collision as elastic or inelastic and provides valid justification?

Elastic, because the total momentum before the collision equals the total momentum after

Inelastic, because some of the initial kinetic energy is converted into nonmechanical energy

Elastic, because some of the initial kinetic energy is converted to other forms of energy, but the total energy is conserved Inelastic, because the total momentum before the collision does not equal the total momentum after

7. A heavy frog and a light frog jump straight up into the air. They push off in such a way that they both have the same initial velocity just as they leave the ground. Air resistance is negligible. Which of the following statements about these frogs is correct?

Both frogs reach the same maximum height. Just as they leave the ground, the heavier frog is moving faster than the lighter frog. The lighter frog goes higher than the heavier frog. The heavier frog goes higher than the lighter frog.

8. A spring is connected to a wall on one end and to a block of mass 1.5 kg on the other. The spring has a negligible mass with a spring constant of 30 N/m. There is negligible friction between the block and the horizontal surface. In the unstretched position, the block rests at x = 0 m. When the block is pulled to x = 0.5 m and released from rest, the block-spring system oscillates between x = 0.5 m and +0.5 m, as shown in the figure. https://cdn.flvs.net/assessment_images/educator_apphysics_v23/06_10_pt1_41_flvs.jpg

The block's period of oscillation would increase if

the block was released from rest at x = 2.0 m t

he spring had a spring constant of 40 N/m t

he block had a mass of 2.0 kg. t

he same block-spring system was hung vertically instead, oscillating between y = 0.5 m and y = 0.5 m

10. A person spins a coin on a horizontal surface. In terms of mechanical energy of the system, for this to be a closed system, the system should include

only the coin the coin and the person only the person the coin, the person, and the table

11. If you want to reduce the momentum of a gas molecule by half, by what factor must you decrease its kinetic energy?

1 2 1/2 1/4

13. Grandfather clocks are designed so they can be adjusted by moving the weight at the bottom of the pendulum up or down. Suppose you have a grandfather clock at home that runs slow. Which of the following adjustments of the weight would make it more accurate?

Move the weight up on the pendulum. Move the weight down on the pendulum. Add more mass to the weight. Increase the amplitude of swing by a small amount.

14. A person pushes a box of mass 3 kg from the bottom of a ramp up to the top. The ramp is inclined at an angle of 30 from the horizontal and is 2.0 m long. The person exerts a force of 112 N on the box parallel to the ramp. What is the approximate amount of work the person does on the box to move it to the top of the ramp? Assume all frictional forces are negligible.

224 J 194 J 112 J 0 J

15. The figure below shows a 6-kg block pushed up an incline that makes a 30 angle with the horizontal. Once the block is pushed a distance of 4.0 m up the incline, the block remains at rest.

https://cdn.flvs.net/assessment_images/educator_apphysics_v23/06_10_pt1_17_flvs.jpg

What is the approximate change in the gravitational potential energy of the block-Earth system from when the block is at the bottom of the incline to when it is held at rest at the top?

235 J 203 J 117 J 0 J

16. Which of the following quantities represents the unit of momentum?

N m kg s/m kg m/s kg m²/s²

^17. A 12-kg sled starts from rest at the top of a hill and slides down. When the sled passes through a point that is 35 m vertically below its starting point, it has a speed of 10 m/s. How much mechanical energy was converted by frictional forces at that point?

0 J 600 J 3,516 J 4,116

18. Person X pushes twice as hard against a stationary brick wall as person Y. Which of the following statements is correct?

Both do positive work, but person X does four times the work of person Y. Both do positive work, but person X does twice the work of person Y. Both do the same amount of positive work. Both do zero work.

19. A solid sphere, a solid cylinder, and a hollow pipe all have equal masses and radii. If the three of them are released simultaneously at the top of an inclined plane and do not slip, in what order do they reach the bottom?

Cylinder, pipe, sphere Pipe, sphere, cylinder Sphere, cylinder, pipe They all reach the bottom at the same time.

20. The graph below shows the potential energy U of a system containing one object that moves along the x-axis. Eight evenly spaced points along the x-axis are labeled. At point 1, the object is moving in the positive x-direction and the mechanical energy of the system is 5.0 J. As the object moves, no energy enters or leaves the system.

https://cdn.flvs.net/assessment_images/educator_apphysics_v23/06_10_pt1_08_flvs.jpg

In which segment does the net force exerted on the object have the greatest magnitude?

1-3

3-4

4-7

7-8