Chapter 5: Work, Energy and Power

Question 1

Define work done

Answer 1

Work done by a force on a body is the product of the force and the displacement in the direction of the force

Question 2

Define energy

Answer 2

Energy is the ability or capacity of a body to do work on another body

Question 3

Define gravitational potential energy

Answer 3

Gravitational potential energy of a body is the energy it possesses due to its position in the gravitational field

Question 4

State the principle of conservation of energy

Answer 4

The principle of conservation of energy states that energy cannot be created or destroyed, but can be converted from one form to another. The total energy in an isolated system remains constant.

Question 5

Define power

Answer 5

Power is defined as the rate of work done

Question 6

Define efficiency

Answer 6

Efficiency is defined as the ratio of useful energy output to the energy input, expressed as a percentage