4. A low-carbon steel plate is 270 mm wide and 25 mm thick. It is reduced in one pass in a two-high rolling mill to a thickness of 20 mm. Roll radius = 600 mm, and roll speed = 30 m/min. Strength coefficient 500 MPa, and strain hardening exponent 0.25. Determine (a) roll force, (b) roll torque, and (c) power required to perform the operation. (10 points)