Question

Calculate the power output exerted by a boy of a mass 92 kg who runs up a staircase to a floor 8m higher in 9s.

Answer 1

Given:

The mass of the boy, m=92 kg

The height of the floor, h=8 m

The time it takes for the boy to climb up the stairs, t=9 s

To find:

The power exerted by the boy.

Step-by-step explanation:

The power exerted is the time rate of transfer of energy. Thus the power is caculated as the ratio of the work done to the time.

Thus the power exerted by the boy is given by,

`P=(W)/(t)=(mgh)/(t)`

Where h is the height of the stairs.

On substituting the known values,

`\begin{gathered} P=(92*9.8*8)/(9) \\ =801.4\text{ W} \end{gathered}`

Final answer:

The power exerted by the boy is 801.4 W