A body is rolling down an inclined plane. If kinetic energy of rotation is 40% of kinetic energy in translatory state, then the body is a

Rotational kinetic energy isKR = 12Iω2 = 12Mk2(vR)2        (I - Mk2 and v = Rω)      = 12Mv2(k2R2)Translational kinetic energy isKT = 12Mv2As per question, KR = 40% KT12Mv2(k2R2) = 40%12Mv2 or k2R2 = 40100 = 25For solid sphere, k2R2= 25Hence, the body is solid ball.