Question

a 1.75 kg stone falls from the top of a cliff and strikes the ground at a speed of 58.8
m/s. what is the height of the cliff?

Answer 1

We can find the height of the cliff from the Law of Conservation of Energy:

$$PE = KE,$$ $$mgh = \dfrac{1}{2}mv^2,$$ $$h = \dfrac{v^2}{2g} = \dfrac{(58.8 \dfrac{m}{s})^2}{2 \cdot 9.8 \dfrac{m}{s^2}} = 176.4 m.$$

Answer:

$h = 176.4 m.$