Physics - W.E.P. Question with Solution | TestHub

A spherical ball of mass $20\mathrm{kg}$ is stationary at the top of a hill of height $100\mathrm{m}$. It rolls down a smooth surface to the ground, then climbs up another hill of height $30\mathrm{m}$ and finally rolls down to a horizontal base at a height of $20\mathrm{m}$ above the ground. The velocity attained by the ball is