Question

Calculate the moment of inertia of the solid sphere having a mass of 28 kg and diameter of 15 cm.

(a) 0.01575 kgm^2

(b) 0.01875 kgm^2

(c) 0.01787 kgm^2

(d) 0.01568 kgm^2

I had been asked this question by my college director while I was bunking the class.

This interesting question is from DC Motors in division Characteristics of DC & AC Motors of Electric Drives

Answer 1

Correct answer is (a) 0.01575 kgm^2

The explanation: The moment of inertia of the solid sphere can be calculated using the formula I=2×miri^2÷5. The mass of the solid sphere and diameter is given. I =(28)×.4×(.0375)^2=.01575 kgm^2. It depends upon the orientation of the rotational axis.