Question

A rod of length $L$ is hinged from one end. It is brought to a horizontal position and released. The angular velocity of the rod, when it is in vertical position is

• A. $\sqrt{\frac{2g}{L}}$
• B. $\sqrt{\frac{3g}{L}}$
• C. $\sqrt{\frac{g}{2L}}$
• D. $\sqrt{\frac{g}{L}}$

Answer 1

Answer: (B)

$\sqrt{\frac{3g}{L}}$

Answer 2

The rod in potential energy = gain in kinetic energy $m g \frac{L}{2}=\frac{1}{2}\left(\frac{m L^{2}}{3}\right) \omega^{2}$ $\omega=\sqrt{\frac{3 g}{L}}$