Question

A pole vaulter approaches the takeoff point at a speed of 8.81m/a. Assuming that only this speed determines the height to which they can rise, find the maximum height which the vaulter can clear the bar.

Answer 1

Use conservation of energy to find the height:

$$KE=PE,\\\space\\ \frac 12mv^2=mgh,\\\space\\ h=\frac{v^2}{2g}=3.96\text{ m}.$$