# Theory of machine

posted by
**Benny antson** on
.

A punching machine carries out of 5 holes per minute each hole of 30 mm diameter in 40 mm thick plate requires 10 Nm of energy/mm2 of the sheared area.The punch has a stroke of 90 mm.Find the power of the motor required if the mean speed of the fly wheel is 20 m/sec.If the total fluctuation of the speed is not to exceed 2 % of the mean speed,determine the mass of the fly wheel.