Question 1

A person lifts a box of mass $$m$$ from the floor and places it on a table of height $$h at $$constant speed. What is the total work done by the person on the box?

Accepted Answer

$$W = mgh$$

Question 2

Which of the following best describes the physical meaning of a negative value for work done by a force on an object?

Accepted Answer

The force acts in the direction opposite to the displacement of the object.

Question 3

A block of mass $$m is $$released from rest at height $$h$$ and slides down a frictionless ramp to a lower height. What is its speed at the bottom of the ramp?

Accepted Answer

$$v = \sqrt{2gh}$$

Question 4

Which of the following is the correct expression for the gravitational potential energy of an object of mass $$m at $$height $$h$$ above the ground?

Accepted Answer

$$U_g = mgh$$

Question 5

A spring with spring constant $$k is $$compressed by a distance $$x. $$What is the potential energy stored in the spring?

Accepted Answer

$$U_s = \frac{1}{2}kx^2$

Question 6

A 2 kg block is released from rest at a height of 5 m. Ignoring air resistance, what is its kinetic energy just before it hits the ground?

Accepted Answer

$$K = 98\ \mathrm{J}$$

Question 7

A ball is attached to a string and pulled back to a height $$h$$ before being released. Neglecting air resistance, what is the maximum height the ball will reach on the other side?

Accepted Answer

It will reach the same height $$h.$$

Question 8

Which of the following statements about energy conservation is correct?

Accepted Answer

The total energy of a closed system remains constant if no external work is done.

Question 9

A block of mass $$m is $$pushed by a force $$F$$ over a distance $$d at an $$angle $$	heta$$ above the horizontal. What is the work done by the force?

Accepted Answer

$$W = Fd \cos 	heta$$

Question 10

A compressed spring launches a block of mass $$m on a $$frictionless surface. If the spring is compressed by $$x$$ and has spring constant $$k$$, what is the block's speed as it leaves the spring?

Accepted Answer

$$v = \sqrt{\frac{k}{m}}x$$

Question 11

A ball rolls down four different shaped ramps from the same height. Which statement is true about the final speed of the ball at the bottom of each ramp (neglecting friction)?

Accepted Answer

The final speed is the same for all ramps.

Question 12

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

Accepted Answer

Kinetic energy

Question 13

A block is pushed up a frictionless incline and comes to rest at height $$h. $$What is the change in the block's kinetic energy?

Accepted Answer

$$\Delta K = -mgh$$

Question 14

If the net work done on a system is zero, what can be said about the system's total energy?

Accepted Answer

The total energy remains constant.

Question 15

A molecular bond breaks, converting chemical potential energy into kinetic energy. Which law does this process illustrate?

Accepted Answer

Conservation of energy

Question 16

A block of mass $$m is $$attached to a spring (spring constant $$k) $$and is compressed by $$x. If $$the block is released from rest, what is its speed when the spring returns to its equilibrium position?

Accepted Answer

$$v = \sqrt{\frac{k}{m}}x$$

Question 17

Which of the following best describes potential energy?

Accepted Answer

Energy stored in an object or system due to its position or configuration.

Question 18

A person pushes a box horizontally across a rough floor at constant speed. Which statement is true about the work done by the person and the friction force?

Accepted Answer

The work done by the person is positive, and the work done by friction is negative.

Question 19

A block of mass $$m is $$dropped from height $$h$$ and lands with speed $$v. $$Which equation correctly relates the gravitational potential energy lost to the kinetic energy gained?

Accepted Answer

$$mgh = \frac{1}{2}mv^2$

Mechanical Potential Energy: Concepts, Applications, and System Analysis

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