**A series of cold rolling pastes is applied to reduce the thickness of a metal plates from 50 mm to 25 mm. The diameter of the rollers is 700 mm and the
coefficient of friction μ = 0.15. The reduction in thickness per sheet (Δh) must be equal to all in all. Calculate the minimum number of passes and the reduction per pass.
(a) With the data of the previous case, you consider that it is necessary to be equal,in all the percent reduction in thickness. Calculate the minimum number of passwords and the reduction per pass.**