Question

what is work done by variable force?

Answer 1

The variable force is more commonly encountered than the constant force.If the displacement Dx is small, we can take the force F (x) as approximately constant and the work done is then
DW =F (x) Dx

For total work, we add all work done along small displacements.

Example: A force F = 3x2start acting on a particle which is initially at rest. Find the work done by the force during the displacement of the particle from x =0m to x = 2m.