Question

Four solid spheres, each having mass m and radius r are placed with their centers on the four corners of a square of side



a. Then the moment of inertia of the system about any side of the square is:

Answer 1

Moment of inertia for 4 spheres =

4(2/5mr2)

Since two of them are at a distance a from axis

We add 2(ma2)

So final m.o.i

4(2/5mr2) + 2(ma2)

=8/5mr2 + 2ma2

.

Feel free to ask for any clarifications

.

Thank you

Answer 2

Answer:

Moment of inertia for 4 spheres =

4(2/5mr2)

Since two of them are at a distance a from axis

We add 2(ma2)

So final m.o.i

4(2/5mr2) + 2(ma2)

=8/5mr2 + 2ma2

.

Feel free to ask for any clarifications

.