Important Terms

1. Work is said to be done when a force acting on a body moves it in the direction of the force.

• Work = FS
• SI unit of work is the joule (J).

1. When we say that a body has energy, we mean that it can do work. SI unit of energy is also joule, the same as work.

Energy exists in various forms such as mechanical energy, heat energy, light energy, sound energy, electrical energy, chemical energy, nuclear energy, etc. Energy from one form can be transformed into another.