Question

A coolie is standing on a railway platform with a suitcase which presses his head with a force of 300N. If this force is considered as the action, which will be the reaction force and what is its magnitude? Find the work done by him if he walks 50m?

Answer 1

1. Work done by a coolie, walking on level road with load on his head, on the load is zero.
2. Work done = Force x displacement

W = F.s = Fs cos θ

where  θ is the angle between the direction of force and the direction of displacement of the object. If they are perpendicular to each other  θ = 90°. We have cos  90° = 0. Therefore
W  = Fxsx0 = 0

Answer 2

work=f.s in the question there is no angle so
w=300×50
w=15000N-M
$w = f.s$