Watts problem-have the answer please help explain!

Question

An elite Tour de France cyclist can maintain an output of 470 Watts during a sustained climb. At this output power, how long would it take a 84 kg cyclist (including the mass of his bike) to climb the famed 1100 m high Alpe d’Huez mountain stage (neglect any friction or drag)

tage? Neglect any friction or drag.

Answer: 1900 s

Answer 1

To calculate the time required, consider that power = change in energy / time.

The type of energy that is changing here is gravitational potential energy which we calculate with the equation mgh. So,

P = (mgh)/t

Rearrange to solve for t:

t = (mgh)/P

and then you'll have your answer!