Question

A body of circular cross-section is placed on a smooth horizontal surface. When a horizontal impulse is given to its highest point, it begins to roll without slipping. The body is a 

(a) ring 

(b) disc 

(c) solid sphere 

(d) hollow sphere

Answer 1

Correct Answer is: (a) ring 

J = mv.

L = Jr = Iω = (k²)(v/r)

or mvr = mk² v/r

or k² = r².