Question

A variable force F acts on a bodywhich is free to move. Thedisplacement of the body is proportional to t′, where t=time. Thepower delivered by F to the body willbe proportional to

A .

t

B .

t2

C .

t3

D .

t4​

Answer 1

I guess this question is from an exam which has multiple choice questions...

Let s be the displacement...

s ∝ t

Since the force is variable, and change in force will directly change the displacement...

s ∝ F

Power delivered :-

P = Fs/t

⇒ P ∝ t