The punching rate of a punching press is 20 holes per minute. It is required to punch a hole of diameter 50 mm on a plate of 20 mm thickness. Press requires 10 N-m of energy per mm of sheared area. Calculate the energy required for punching work per second. (Marks: 02)

The punching rate of a punching press is 20 holes per minute. It is re

1.	The punching rate of a punching press is 20 holes per minute. It is required to punch a hole of diameter 50 mm on a plate of 20 mm thickness. Press requires 10 N-m of energy per mm of sheared area. Calculate the energy required for punching work per second. (Marks: 02)
A.	628318.2 Nm/s
B.	10471.97 Nm/s
C.	31416 Nm/s
D.	none of the above
Answer» C. 31416 Nm/s