Physics · PYQ NEET UG 2016(2)
हिन्दीA light rod of length \( l \) has two masses \( m_1 \) and \( m_2 \) attached to its two ends. The moment of inertia of the system about an axis perpendicular to the rod and passing through the centre of mass is
Correct answer · Option 2
\( \frac{m_1 m_2}{m_1 + m_2} l^2 \)
Explanation
Distances of masses from CM are \( r_1 = \frac{m_2 l}{m_1 + m_2} \) and \( r_2 = \frac{m_1 l}{m_1 + m_2} \). \( I = m_1 r_1^2 + m_2 r_2^2 = \frac{m_1 m_2}{m_1 + m_2} l^2 \).