Physics
it is estimated that 1.0 kg of body fat will provide
3.8 × 107 j of energy. a 60-kg mountain climber decides
to climb a mountain 4000 m high.
(a) how much work does the climber do against
gravity in climbing to the top of the mountain?
the answer for this is 2.4x10^6
(b) if the body’s efficiency in converting energy stored as
fat to mechanical energy is 25%, determine the
amount of fat the climber will use up in providing the
energy required to work against the force of gravity.
the answer is 0.25kg
i got a) but i don't understand how to do b)