A small object of uniform density rolls up a curved surface with an initial velocity 'υ'. It reaches upto a maximum height of 3υ24gwith respect to the initial position. The object is

The kinetic energy of the rolling object is converted into potential energy at heighth=3v24gSo by the law of conservation of mechanical energy, we have12Mv2+12Iω2=Mgh 12Mv2+12IvR2=Mg3v24g           ∵ω=vR 12Iv2R2=34Mv2−12Mv2 12Iv2R2=14Mv2   or   I=12MR2Hence, the object is disc.