A thin uniform rod (length 1.2 meter, mass = 2.0 kg) is pivoted regarding a horizontal, frictionless pin through one end of the rod. (The moment of inertia of the rod about this axis is ML 2/3.) The rod is released when it makes an angle of 37 degree by the horizontal. What is the angular acceleration (in rad/s^2) of the rod at the instant it is released?