hi, i am doing a project on frame tilting arrangement where the sheet metal stacks mounted on a shaft have to be rotated by 180 degrees. the mass of the shaft is 15 tonnes. to calculate the torque required i found the mass moment of inertia and multiplied it by angular acceleration. the total time taken to rotate the stacks is 25 minutes.so the speed is extremely slow. since the setup reaches the speed instantaneously, for calculating angular acceleration i took time as 0.1 sec(i don know whether this is right). i got very low torque value and also low power.(it came in watts!). i donot know the mistake . please help asap.