Question

A circular disc has mass M and radius R. Moment of inertia about its diameter will be: *​

Answer 1

MR² / 4

Explanation:

R.E.F image 

Solution We know that moment of inertia of 

disk about A1(I1)=MR2²/2

Applying Perpendicular Aois 

theorem, 

I1=I2+I3

MR²/ 2 =I2+I3

By the symmetry of disk, we can 

conclude that 

I2=I3

So, 2MR2=2 I2 or ( 2 i2)

⇒I2=I3=MR²/4