Question

derive the expression for the work done when the displacement is in the direction of force

Answer 1

consider a body at "A" acted upon by the force'F'such that it gets displaced through a distance"S"in the direction of the force. If "W"
is the work done, then
work done is directly proportional to force
...........................(i)
work done is directly proportional to displacement. ..............(ii)

combining (i) and (ii),
work done is directly proportional to force and displacement


$w = k \times f \times s$