Science Made Easy
Work and Energy
Introduction
Work done
Work done on an object is defined as the product of the magnitude of the force acting on the body and the displacement in the direction of the force. W = F.s
If a force acting on a body causes no displacement, the work done is 0. For example, pushing a wall.
Two conditions need to be satisfied for work to be done:
(i) A force should act on object
(ii) The object must be displaced
• W = Fs
If F = 1 N and s = 1 m
W= 1 N x 1 Nm
W = 1 Nm
1j =1 Nm
- 1 J is the amount of work done on an object when a force of 1 N displaces it by 1 m along the line of action of the force.
• Work done has only magnitude and no direction i.e., work is a scalar quantity.
• SI unit of work is joule (J).
• 1 joule (one joule)
