\(\therefore E = \frac{1}{2}m{v^2} + \frac{1}{2}I{\omega ^2}\)
\(where\,\omega = \frac{V}{r}\,and\,I = \frac{2}{5}m{r^2}\,for\,solid\,sphere.\)
\(\therefore K.E. = \frac{1}{2}m{v^2} + \frac{1}{2}\left( {\frac{2}{5}m{r^2}} \right).\frac{{{V^2}}}{{{r^2}}}\)
\( = \frac{1}{2}m{v^2} + \frac{1}{5}m{v^2} = \frac{7}{{10}}m{v^2} = \frac{7}{{10}} \times 1 \times {1^2}\)
\( = \frac{7}{{10}}J\)
$\left(g=10 \,m / s ^{2}\right.$ નો ઉપયોગ કરો.)