5.1 Work
Force and distance are two essential elements of work. When a constant force acting on a body moves it through some distance, we say that the force has done work.
lightbulbWork is defined as the product of the magnitude of force and the distance covered in the direction of force.
Consider a block of wood lying on a table. If we exert a force F on the block to move it through a distance S in the direction of force, then the work W done by the force is:
Work = Magnitude of force × Distance
W = F × S ............ (5.1)
From Eq. (5.1), it can be concluded that if some force is acting on a body but there is no displacement, then no work is done. For example, a man pushing hard against a wall does no work because the wall remains fixed in place.
Similarly, if a force acting on the body is zero and the body is moving with uniform velocity, work will be zero.