meter stick urgent help

Question

A uniform meter stick of mass 1.5kg is attached to the wall by a frictionless hinge at one end. On the opposite end it is supported by a vertical massless string such that the stick makes an angle of 40o with the horizontal.

a) Find the tension in the string and the magnitude and direction of the force exerted on the stick by the hinge.

b) Suppose the string is cut. Find the angular acceleration of the stick immediately thereafter.

Answer 1

To do this problem, work out the opposing torque created by the tension of the string and the force of gravity (assume it operates at the center of gravity for the stick). The sum of the torque should be zero. Once the string is cut, the torque due to gravity will create angular acceleration according to the torque from gravity and the moment of inertia for the stick.