A small object of uniform density rolls up a curved surface with an initial velocity `v`. It reached upto maximum height of `3v^(2)//4g` with respect to the initial position. The object is -
.

Options

A. ring
B. solid sphere
C. hollow sphere
D. disc

Answer

D

Explanation

By the concept of energy conservation
`1/2mV^(2)+1/2I(V^(2))/(R^(2))=3/4mV^(2)`
`:. 1/2I(V^(2))/(R^(2))mV^(2)-1/2mV^(2)=1/4mV^(2)`
`implies I=1/2mR^(2)`