A uniform solid disc of mass and radius is carefully reshaped into a thin circular…

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

Problem

A uniform solid disc of mass

2\,\text{kg}

and radius

0.20\,\text{m}

is carefully reshaped into a thin circular hoop of the same radius, the mass remaining unchanged. What is the ratio

\dfrac{I_{\text{hoop}}}{I_{\text{disc}}}

about the central axis perpendicular to the plane? (a)

0.5

(b)

1

(c)

2

(d)

1.5