A machine has to carry out punching operation at the rate of 10 holes/min. It does 6 N-m of work per sq mm of the sheared area in cutting 25 mm diameter holes in 20 mm thick plates. A flywheel is fitted to the machine shaft which is driven by a constant torque. The fluctuation of speed is between 180 and 200 r.p.m. Actual punching takes 1.5 seconds. Frictional losses are equivalent to 1/6 of the work done during punching. Find:

(a) Power required to drive the punching machine [5 marks]

(b) Mass of the flywheel, if radius of gyration of the wheel is 450 mm. [5 marks]