Four masses (2kg 3kg 1kg and 2kg) are arranged on a square of side 1.2 m. What is the moment of inertia if the axis of rotation is at the center of the square? What is the moment of inertia if you make the axis of rotation through mass 2kg (this mass cannot contribute to moment of inertia because its the origin of axis of rotation)

Thank you!

1 answer

a. through the center:
Itotal=2r^2+3r^2 + sum them all. r is distance from center to corner.

b. same way, except each distance is different this time. OR you can use the parallel axis theorem.