Question

How much power is required for a 60 kg student to walk up 40 m of stairs in 90 seconds?

Answer 1

The energy that the student shoud use in order to climb the stairs is equal to its increase in gravitational potential energy:

`W= \Delta U= mg \Delta h`
where m is the mass of the student, g the gravitational acceleration and
`\Delta h` the variation of height. Plugging numbers into the equation, we find

`W=(60 kg)(9.81 m/s^2)(40 m)=23544 J`

The power required for the student to climb the stairs is equal to the work done divided by the time taken:

`P= (W)/(t)= (23544 J)/(90 s)=262 W`