Work is defined as the force acting on a body which is responsible for the displacement of the body. Work is measured as a constant force and is the dot product of force and displacement.
W = F.S.cosq
- F is the force
- S is the displacement
- q is the angle between F and S
Work is a scalar quantity and is the product of two vector quantities. Depending on the value of q, there are three types of work:
- When q = 0°, work is said to be positive. Stretching of the spring is an example of positive work as the force is acting in the direction of displacement of the spring.
- When q = 180°, work is said to be negative. The frictional force is an example of negative work as the force is acting in the opposite direction.
- When q = 90°, work is said to be zero. For a body moving a circular path with a centripetal force acting on it with zero speed, the force will be at the right angle