Question
A uniform rod of length l and mass m is free to rotate in a vertical plane about A. The rod initially in horizontal position is released. The initial angular acceleration of the rod is: (Moment of inertia of rod about A is 
)
Solution
A.
The moment of inertia of the uniform rod about an axis through the end and perpendicular to length is
where m is mass of rod and l its length.
Torque 
acting on centre of gravity of rod is given by
or 
