Question

Four spheres each of mass M and diameter 2a are placed at the corners of square of side b as shown below Calculate the moment of inertia ab​

Answer 1

Moment of Inertia (MOI) of sphere about centre of mass =

52Ma 2

Using parallel axis theorem, I=I

cm+Mx2

, Where I cm

In MOI about centre of mass and x is distance between centre of mass and axis of rotation.

⇒ MOI of system about one side of the square =2( 52 Ma 2)+2( 52Ma 2+M )= 58

So,

Ma 2+2Mb 2