Calculating Tension in a Flywheel Drive Belt

[chevyboy86]

An electric motor turns a flywheel through a drive belt that joins a pulley on the motor and a pulley of the flywheel. The flywheel has a mass of 80 kg and a diameter of 1.25m. Its pulley has a much smaller mass and a radius of .230m. the tension in the upper (taut) part of the belt is 135N and the flywheel has a clockwise angular acceleration of 1.67 rad/s2. Find tension in lower belt.

The answer is 21.5N but I can't figure out the equations to get the answer.

 

[berkeman]

The difference in tension between the upper and lower belts will provide the net torque that causes the clockwis angular acceleration. Draw a drawing of the forces and radii, etc., and see where you get to...