determine merchant's constant for aluminium from given data

Question

Determine the Merchants constant ‘C’ (shear angle relation) for aluminium from the following orthogonal machining data. rake angle 35⁰ and an uncut chip thickness 0.15mm, the values of F_c and F_t are found to be 200 and 90 N respectively. The average chip thickness is also measured and found to be 0.3 mm, width of cut 2.5mm and cutting velocity 30m/min.