A punching press is required to punch 400 mm diameter holes in a plate of 15 mm thickness at a rate of 30 holes per minute. It requires 0.60 kgf-m of energy per mm2 of sheared area. Determine the moment of inertia of the flywheel if the punching takes one-tenth of a second and the r.p.m. of the flywheel varies from 160 to 140.