First slide
Moment of intertia
Question

The moment of inertia of a cylinder about its own axis is equal to its moment of inertia about an axis passing through its centre and perpendicular to its length. The ratio of length to radius is

Difficult
Solution

Let the moment of inertia of the cylinder about its own axis AB is I1, and moment of inertia about an axis passing through its centre and perpendicular to its length be I2.Then 
I1=I2
or MR22=MR24+ML212 or R24=L212

or L2R2=124=3  or  LR=31

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App