Answer part b please

Question 1 (25 marks) (a) A steel sphere of 5 mm radius is loaded against a thick plate of the same material. The yield strength of the steel is 1.0 GPa. Stating any assumptions that you make, calculate the applied load and the mean contact pressure at the onset of subsurface yield in the plate. Calculate the depth below the surface at which yield initiates (for steel E = 210 GPa and v=0.3). (13 marks) (b) In order to improve the reliability of a cam and follower it was decided to reduce the maximum contact pressure to 70% of its current value by changing the geometry of the contact (all other parameters remain the same). The current contact consist of two cylinders with parallel axes (i.e., a line contact); one cylinder has a radius of 80 mm while the other has a radius of 20 mm. To what value would the radius of the smaller cylinder need to be changed to achieve the target contact pressure? (12 marks)