Problem #2 (15 points) In turning, specific cutting energy (HPs, in hp-min/inch³) can be given in terms of feed rate (fr, in inch/rev), depth of cut (d, in inch) and the cutting force (Fc, in lb) as: HPs = F(396,000fd). Explain how the constant 396,000 was obtained. Problem #3 (20 points) Consider the following cutting conditions in a turning operation are: cutting speed of 200 ft/min, feed rate of 0.005 inch/rev, and depth of cut of 0.01". What is the material removal rate? Write the corresponding unit of the material removal rate.