3. A series of cold rolling operations are to be used to reduce the thickness of a plate from 50 mm down to 25 mm in a reversing two-high mill. Roll diameter = 700 mm and coefficient of friction between rolls and work 0.15. The specification is that the draft is to be equal on each pass. Determine: (a) minimum number of passes required, and (b) draft for each pass? Assume that the percent reduction were specified to be equal for each pass, rather than the draft. (a) What is the minimum number of passes required? (b) What is the draft for each pass?