Question

A rod PQ of mass M and length L is joined at P. Rod is kept horizontal with the help of a massless string joined at Q figure. When string is cut, then initial angular acceleration of the rod is:

\((a)\ \frac{3g}{2L}\)

\((b)\ \frac{g}{L}\)

\((c)\ \frac{2g}{L}\) 

\((d)\ \frac{2g}{3L}\)

Answer 1

Correct option is : \((a)\ \frac{3g}{2L}\)

When the string attached with end Q is cut, then torque acting on the rod,

\(\tau =\frac{L}{2}\)

Moment of inertia of the rod, about P