Question

The ratio of radius of gyration of a solid sphere of mass M and radius R about its own axis to the radius of gyration of the thin hollow sphere of same mass and radius about its axis is:

• A. 5:2
• B. 3:5
• C. 5:3
• D. 2:5

Answer 1

Answer: (B)

3:5

Answer 2

The correct option is (B): 3:5
The radius of gyration: K=$\sqrt {\frac{I}{m}}$
$\frac{K_{solid\,sphere}}{K_{hollow\,sphere}}=\frac{\sqrt{(2mR^2/5m)}}{\sqrt{(2mR^2/3m)}}$
=3:5