JEE Mains · Physics · STD 11 - System of particles and rotational motion
- JEE Mains 2019
- Hard
- MCQ
A rigid massless road of length \(3l\) has tow masses attached at each end as shown in the figure. The rod is pivoted at point \(P\) on the horizontal axis (see figure). When released from initial horizontal position, its instantaneous angular acceleration will be

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Answer & Solution
Correct Answer
(A) \(\frac{g}{13l}\)
Step-by-step Solution
Detailed explanation
\(\alpha = \frac{\tau }{I}\)
\( = \frac{{5{M_o}g\ell - 4{M_o}g\ell }}{{5{M_o}{\ell ^2} + 2{M_o}4{\ell ^2}}}\)
\( = \frac{{{M_o}g\ell }}{{13{M_o}{\ell ^2}}}\)
\( = \frac{g}{{13\,\ell }}\)
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