Work done by a variable force o
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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 = 3x 2 start 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.