Given is a 6' long 40 lb bar hung horizontally by a pin O at its end. It is released from its horizontal position and hits a stopper after reaching a 30 degree angle with the horizontal position at which it started. I am asked to find the value x for which the angular velocity is a maximum and also the corresponding angular acceleration alpha Sum of the torques about O=I(alpha) a(t)=r*alpha I honestly do not know where to start with this one. do I start by summing moments about O? Thanks in advance for any help.