Question

A uniform thin rod of mass 'm' and length L is held horizontally by two vertical strings attached to the two ends. One of the string is cut. Find the angular acceleration soon after it is cut

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

Answer 1

The correct option is A $\frac{g}{2L}$

Just after the cutting of the string,

Taking Moment about one end of the rod which is attached to the string,

$mg\times \frac{l}{2}=I\times \alpha$ , ( Where $I=\frac{m{l}^2}{3}$ )

$\Rightarrow \alpha =\frac{3g}{2l}$