Question

Two identical semicircular discs of mass 'm' each and radius 'R" are placed in the XY (horizontal) plane and the YZ (vertical) plane, respectively. They are so placed that they have their common diameter along the Y-axis. Then the moment of inertia ($I_n$) of the system about the approximate axis is given by ($I_n$ refers to moment of inertia about axis n-where n is X, Y, Z)

• A. $I_X=\frac{1}{2}m{R}^2$
• B. $I_Y=\frac{1}{2}m{R}^2$
• C. $I_Z=\frac{3}{4}m{R}^2$
• D. $I_X=I_Y=I_Z$

Answer 1

Answer: (B), (C)

The correct options are
B $I_Y=\frac{1}{2}m{R}^2$
C $I_Z=\frac{3}{4}m{R}^2$