JEE Mains · Physics · STD 11 - System of particles and rotational motion
- JEE Mains 2019
- Hard
- MCQ
Two identical spherical balls of mass \(M\) and radius \(R\) each are stuck on two ends of a rod of length \(2R\) and mass \(M\) (see figure). The moment of inertia of the system about the axis passing perpendicularly through the centre of the rod is

Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(\frac{{137}}{{15}}M{R^2}\)
Step-by-step Solution
Detailed explanation
\(\begin{array}{l}
l = 2\left[ {\frac{2}{5}M{R^2} + M4{R^2}} \right] + M\frac{{4{R^2}}}{{12}}\\
\,\,\, = M{R^2}\left[ {\frac{1}{3} + \frac{4}{5} + 8} \right] = \frac{{137}}{{15}}M{R^2}
\end{array}\)
l = 2\left[ {\frac{2}{5}M{R^2} + M4{R^2}} \right] + M\frac{{4{R^2}}}{{12}}\\
\,\,\, = M{R^2}\left[ {\frac{1}{3} + \frac{4}{5} + 8} \right] = \frac{{137}}{{15}}M{R^2}
\end{array}\)
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