Work, Energy, and Power

Question 1

Define work:

Answer 1

Work is the product of the displacement and the component of the force parallel to the displacement.

Question 2

Define gravitational potential energy:

Answer 2

Gravitational potential energy is the energy an object possesses due to its position relative to a reference point.

Question 3

Define kinetic energy:

Answer 3

Kinetic energy is the energy an object has as a result of its motion.

Question 4

Define mechanical energy:

Answer 4

Mechanical energy is the sum of gravitational potential energy and kinetic energy at a point.

Question 5

State the principle of the conservation of mechanical energy:

Answer 5

The principle of the conservation of mechanical energy states that in the absence of dissipative forces, the mechanical energy of an object is constant.

Question 6

State the law of conservation of energy:

Answer 6

The law of conservation of energy states that the total energy in a system cannot be created nor destroyed; only transformed from one form to another.

Question 7

State the work-energy theorem:

Answer 7

The work-energy theorem states that the work done by a net force on an object is equal to the change in the kinetic energy of the object.

Question 8

Define power:

Answer 8

Power is the rate at which work is done.

Question 9

Define one watt:

Answer 9

One watt is the amount of power used when one joule of work is done in one second.

Question 10

Define efficiency:

Answer 10

Efficiency is the ratio of output power to input power.