Question

A stone of mass 50kg released from a heigth of 2m above the ground level if the stone falls freely to a heigth of 5m above the ground, its velocity is?

Answer 1

From the conservation of enegy:

$$mgH=mgh+0.5mv^2$$

The velocity:

$$v=\sqrt{2g(H-h)}$$

$$v=\sqrt{2(9.8)(20-5)}=17\frac{m}{s}$$