Question

A 60 kg student climbs a flight of stairs 1.2 meters high in 6 seconds. What is the power output of the student?

Answer 1

Step-by-step explanation:

Power is defined as the rate at which the work is done:

`P=(\Delta W)/(\Delta t)`

where P = power, ΔW = work done, and Δt = time interval in which this work is done.

Now in our case, when the 60 kg student climbs 1.2 meters, the amount of work he does is

`=705.6J`

Hence, the student did a work of 705.6 J.

In what time interval did he do this amount of work? We are told that he climbed the stairs in 6 seconds; therefore, Δt = 6 s. Hence,

`P=(\Delta W)/(\Delta t)=(705.6J)/(6s)`
`\Rightarrow\boxed{P=117.6W}`

Hence, the power output of the student is 117.6 watts.