A composite body is made by rigidly fixing a thin circular hoop of mass and radius…

PHYSICS · Single correct · A Level · Physics · Engineering physics · Engineering physics

Problem

A composite body is made by rigidly fixing a thin circular hoop of mass

2M

and radius

R

concentrically on top of a solid disc of mass

M

and the same radius

R

. What is the ratio of the moment of inertia of the composite body to that of the hoop alone about the common central axis? (a)

\dfrac{3}{2}

(b)

\dfrac{5}{4}

\dfrac{4}{3}