The amount of energy needed to power a 0.10-kw bulb for one minute would be just sufficient to lift a 1.0-kg object through a vertical distance of

612.2 m

Explanation:

The work needed to lift the object is equal to its increase in gravitational potential energy:

(1)

where

m = 1.0 kg is the mass

g = 9.8 m/s^2

is the vertical distance

The power provided is

In one minute (t = 1 min = 60 s), the work provided is

Substituting this into (1) and solving for , we find

multiple

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle