An object of uniform density rolls up the curved path with the initial velocity v_o as shown in the figure. If the maximum height attained by an…

An object of uniform density rolls up the curved path with the initial velocity $\displaystyle v_{\mathrm{o}}$ as shown in the figure. If the maximum height attained by an object is $\displaystyle \frac{7 v_{\mathrm{o}}^2}{10 \mathrm{~g}}$ ( $\displaystyle \mathrm{g}=$ acceleration due to gravity), the object is a $\displaystyle \_\_\_\_$.