A man whose mass is 74.7 kg runs up a flight of stairs and has a vertical gain of 19.9 m in a time of 12.5 s.
a. What power, in watts, is supplied by the force pushing up on the man? (Ignore gains or losses in kinetic energy.)
b. Suppose the man’s body is 41.2% efficient, so that just 41.2% of the energy supplied by his body is converted into mechanical power. How much total power is expended by his body, in watts? (P=___W)
