Question

A man with a mass of 90 kg is skiing at a speed of 20 m.s^-1 when he reaches the bottom of a 20 m slope. He goes up the slope without exerting any other forces to help him. Ignore friction. Will he reach the top of the slope? Show all calculations.

Answer 1

The law of conservation of energy gives

$$\frac{mv_0^2}{2}=mgh$$

So

$$h=\frac{v_0^2}{2g}=\frac{20^2}{2×9.8}=20.4\:\rm m$$

Since $h>20 \;\rm m$, so the man will reach the top of the slope.