Question 1

A 100 kg box slides down a frictionless incline. If the gravitational potential energy at the top is 1500 J, what is the kinetic energy of the box at the bottom of the incline?

Accepted Answer

1500 J

Question 2

A 20 N horizontal force is applied to a 4.0 kg box, moving it 3.0 meters across a frictionless surface. What is the magnitude of the work done by the force?

Accepted Answer

60 J

Question 3

An 8000 kg satellite is launched from Earth. What initial speed is needed for the satellite to escape Earth's gravity (reach infinite distance), neglecting air resistance? Use $$v_{esc} = \sqrt{2GM/R}.$$

Accepted Answer

11,180 m/s

Question 4

A 1800 kg car moving at 20 m/s hits an uncompressed spring with spring constant $$k = 2.0 	imes 10^6$ N/m. What is the maximum compression x$ of the spring? Use $$\frac{1}{2}$$mv^2$$ = \frac{1}{2}$$kx^2.$$

Accepted Answer

0.80 m

Question 5

A 2.0 kg ball is moving at 4.0 m/s WEST. What is its momentum?

Accepted Answer

8.0 kg m/s WEST

Question 6

A 3.0 kg object moving right at 4.0 m/s collides perfectly inelastically with a 6.0 kg object moving left at 2.0 m/s. What is the total kinetic energy after the collision?

Accepted Answer

12 J

Question 7

Which of the following is NOT a fundamental form of energy?

Accepted Answer

translational energy, rotational energy, and vibrational energy

Question 8

Two objects collide and stick together. Which statement is FALSE?

Accepted Answer

kinetic energy is conserved

Question 9

A person pushes a box across a horizontal floor at constant speed. What is true about the work done by the applied force?

Accepted Answer

The applied force does positive work

Question 10

A roller coaster car starts at the top of a hill with zero speed. As it rolls to the bottom, what happens to its total mechanical energy (ignoring friction)?

Accepted Answer

It remains constant as energy is conserved

Question 11

A forklift raises a pallet to a shelf. A second forklift raises an identical pallet to the same shelf but takes twice as long. Ignoring friction, how do the amounts of work done by the two forklifts compare?

Accepted Answer

Both do the same amount of work

Question 12

Two ice skaters, initially at rest, push off each other. Skater A moves left and Skater B moves right. What is the total momentum of the system after they push off?

Accepted Answer

Zero, because momenta in opposite directions cancel

Question 13

A person carries a heavy box across a flat floor at constant height and speed. How much work does the person do on the box against gravity?

Accepted Answer

Zero, because there is no vertical displacement

Question 14

A stretched spring is released and launches a ball. Which energy transformation occurs?

Accepted Answer

Elastic potential energy \rightarrow kinetic energy

Question 15

A large truck and a small car travel at the same speed. Which statement about their momenta is correct?

Accepted Answer

The truck has greater momentum because it has greater mass

Question 16

You push against a wall with all your strength for one minute, but the wall does not move. How much work have you done on the wall?

Accepted Answer

Zero, because there was no displacement of the wall

Question 17

A ball is dropped from a height and bounces to a slightly lower height each time. Why does it not return to its original height?

Accepted Answer

Some mechanical energy converts to thermal energy and sound during impact

Question 18

A ball of clay traveling east collides with and sticks to an identical ball of clay at rest. What best describes the result?

Accepted Answer

The combined mass moves east, but slower than the original ball

Question 19

A pendulum swings back and forth. At which point does it have the greatest kinetic energy?

Accepted Answer

At the lowest point of its swing

Physics Exam Study Guide: Work, Energy, and Momentum

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