Hey Folks I have rather a silly doubt i guess... It goes like this Consider a disc rotating about a fixed axis with constant angular velocity. Which means it has no angular acceleration ie it must be 0. Now since Torque=(moment of inertia)*(angular acceleration). hence the torque acting on the disc must be zero. But i have come across situations where torque comes into the picture while calculting the power produced by say a Turbine(rotating with a constant angular velocity) . where Power=(torque)*(angular velocity)...?? Why is it so? isn't the torque 0 on circular bodies rotating with constant angular velocity?