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)

What is magnetic flux? explain faraday's law of induction.

We have a colorless transparent liquid. it looks like water. we seperated it into a solid and a liquid by evaporration and condention was this a chemichal or a physical seperation a. chemical seperation b. physical seperation

Your starship, the aimless wanderer, lands on the mysterious planet mongo. as chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 14.0 m/s returns to the ground in 5.70 s ; the circumference of mongo at the equator is 2.20×10^5 km ; and there is no appreciable atmosphere on mongo. (a) the starship commander, captain confusion, asks for the following information: what is the mass of mongo? (b) if the aimless wanderer goes into a circular orbit 2.20×10^4 km above the surface of mongo, how many hours will it take the ship to complete one orbit? (c) an unmanned spacecraft is in a circular orbit around the moon, observing the lunar surface from an altitude of 44.0 km . to the dismay of scientists on earth, an electrical fault causes an on-board thruster to fire, decreasing the speed of the spacecraft by 23.0 m/s . if nothing is done to correct its orbit, with what speed (in km/h) will the spacecraft crash into the lunar surface?