Question

A 67.2kg Student runs up the stairs of a football stadium to a height of 10.1 m above the ground in 12.2s. What is the power of the student in KW? And in hp?

Answer 1

I got `0.55kW~~0.73 \ "hp"`

Explanation:

Well, we know that the equation for power is

`P=W/t`

where `W` is the total work done and `t` is the time in seconds

Work is defined as the force multiplied by the distance.

`W=F*d`

Here, the force is the student's weight in newtons, and `d=10.1`

`:.W=67.2*9.81*10.1=6658.2J`

So,

`P=(6658.2J)/(12.2s)=545.75W`

We know that `1kW=1000W`, so `P=0.54575~~0.55kW`

We also need to know that `1 \ "hp"=745.7W`, so the power in horsepower is `545.75/745.7=0.73 \ "hp"`