Energy and Conservation of Energy

Energy that is due to the motion of an object is

• kinetic energy.

• potential energy.

• gravitational potential energy.

• elastic potential energy.

Energy stored in the gravitational field of interacting bodies is

• kinetic energy.

• nonmechanical energy.

• gravitational potential energy.

• elastic potential energy.

Energy associated with a compressed or stretched object is

• kinetic energy.

• potential energy.

• gravitational potential energy.

• elastic potential energy.

How does the kinetic energy of an object change if the object’s speed doubles?

• The kinetic energy decreases to half its original value.

• The kinetic energy doubles.

• The kinetic energy increases by a factor of 4.

• The kinetic energy does not change.

The work-kinetic energy theorem states that

• the net work done on an object equals the kinetic energy of the object. W_net = KE

• the net work done on an object equals the change in the kinetic energy of the object. W_net = ∆KE

• the change in the net work done on an object equals the kinetic energy of the object. . ∆W_net = KE

• the change in the net work done on an object equals the change in the kinetic energy of the object. . ∆W_net = ∆KE

Which of the following is true of the conservation of energy in a closed system?

• Kinetic energy is always conserved.

• Potential energy is always conserved.

• Mechanical energy is always conserved.

• Total energy is always conserved.

The mechanical energy of a system of objects is

• the sum of kinetic energy and gravitational potential energy.

• the sum of kinetic energy and elastic potential energy.

• the sum of kinetic energy and all relevant forms of potential energy.

• the sum of all forms of energy.

Friction does -400 J of net work on a moving car. How does this affect the kinetic energy of the car?

• The kinetic energy increases by 400 J.

• The kinetic energy decreases by 400 J.

• The kinetic energy decreases by 160 kJ.

• The kinetic energy does not change.

Mechanical energy is not conserved when

• gravitational potential energy is converted to kinetic energy.

• kinetic energy is converted to gravitational potential energy.

• kinetic energy is converted to elastic potential energy.

• friction is not negligible.

If mechanical energy is conserved in a system, the energy at any point in time can be in the form of

• kinetic energy.

• gravitational potential energy.

• elastic potential energy.

• all of the above