Work Energy And Power

A stone of mass 1 kg tied to a light inextensible string of length $L=\frac{5}{3} m$ is rotating in a circular path of radius $L$ in a vertical plane. If the ratio of maximum tension in the string to the minimum tension in the string is 3 , the speed of the stone at the highest point of the circle is ( $\mathrm{g}=$ acceleration due to gravity)