A solid sphere of mass 1.5kg rolls on a frictionless horizontal surface, its centre of mass moving at a speed of $5{\mathrm{ms}}^{-1}$. Then it rolls up an incline of${30}^0$ to horizontal. If the height attained by the sphere before it stops is $\left(\frac{7}{\mathrm{x}}\right)\mathrm{m}$ then find $\mathrm{x}.\left(\mathrm{g}=10{\mathrm{ms}}^{-2}\right)$