Chapter 6, Problem 81GP

To determine

The minimum power output.

Answer to Problem 81GP

Solution: $338W$

Explanation of Solution

Given

The mass of the athlete is $m=62\text{kg}$ .

The vertical distance moved by the athlete is $h=5.0\text{m}$ .

Time taken to climb this distance is $t=9.0\text{s}$ .

Formula used

The power can be expressed as:

  $\text{Power=}\frac{\text{Work}\text{Done}}{\text{Time}}$ .

Calculations

The work done by athlete

  $\begin{array}{l}W=mgh\\ W=62\times 9.8\times 5.0\text{J}\\ W=3038\text{J}\end{array}$

The power output,

  $\begin{array}{l}P=\frac{W}{t}\\ P=\frac{3038}{9.0}\text{W}\\ P\approx 338\text{W}\end{array}$

Conclusion:

The approximate power output is $338W$ .