Question

How is the power related to the speed at which a body can be lifted?

Answer 1

Power = Work / time
= F x s / t
= F x v (since s / t = v)

So we can say, power = force x speed (or velocity)

Given, power of man = 100 W
g = 10 m/s2
v (speed) = 1 m/s

Let mass of object be m

Now, P = F x v
or, P = m x a x v

ATQ,

100 = m x 10 x 1
m = 100 / 10
m = 10

The man will be able to lift 10 kilograms working at the power of 100W at constant speed of 1 m/s, when g = 10 m/s2.