Physics

Problem

A ball of mass

0.5\,\text{kg}

is released from rest at a height of

8\,\text{m}

above the ground. Take

g = 10\,\text{m/s}^2

. Find its speed when its potential energy has decreased by

20\,\text{J}

. a)

12.6\,\text{m/s}

8.9\,\text{m/s}

6.3\,\text{m/s}

4.5\,\text{m/s}