Question

In the figure shown find the moment of inertia of a plate having mass M, length l and width b about axis 1,2,3 and 4. Assume that mass is uniformly distributed.

Answer 1

Moment of inertia of the plate about axis 1
(by taking rods perpendicular to axis 1) $I_1=M{b}^2/3$
Moment of inertia of the plate about axis 2.
(by taking rods perpendicular to axis 2) $I_2=M{l}^2/12$
Moment of inertia of the plate about axis 3.
(by taking rods perpendicular to axis 3) $I_3=M{b}^2/12$
Moment of inertia of the plate about axis 4.
(by taking rods perpendicular to axis 4) $I_4=M{l}^2/3$