Question

Surface mass density of a disc is given by $\sigma = kr^2$ (where r is distance from centre) find moment of inertia about axis passing through the centre and perpendicular to plane -

• A. $\frac{k \pi r^6}{3}$
• B. $\frac{k \pi r^6}{6}$
• C. $\frac{ 2 k \pi r^6}{5}$
• D. $\frac{ 3 k \pi r^6}{5}$

Answer 1

Answer: (A)

$\frac{k \pi r^6}{3}$

Answer 2

Answer (a) $\frac{k \pi r^6}{3}$