Question

How is work done by a force measured when the force: 

1. is in the direction of displacement? 

2. is in an angle to the direction of displacement?

Answer 1

1. When force is in the direction of displacement θ= 0°, then cos0 = 1. 

Hence, the work done by a force measured in the direction of displacement is W = F x S The work done is maximum and positive. 

2. When the displacement is in the direction making an angle . with the direction of force, Work done = Component of force in the direction of displacement x displacement 

W.F = cosθ x s .