In a straight turning operations the diameter of a workpiece is reduced from 50 mm 40 mm using a feed rate of 0.1 mm/rev. The cutting tool used for the process has a normal working rake angle of 15°, clearance angle of 4° and a lead angle of 90°. The cutting force of 1200 N and a thrust force of 660 N is measured during cutting operations. The workpiece material was stainless steel with a density of 7850 Kg/m³, thermal conductivity is 15 J/smK, specific heat is 480 J/kgK. The width of the secondary deformation zone divided by the chip thickness wo is assumed to be 0.2 for the above mentioned cutting conditions. The chip/tool contact length is measured as 1.5 mm. (a) Calculate the temperature rise in the primary deformation zone (b) Calculate the temperature rise in the secondary deformation zone (c) Calculate the maximum temperature if the room temperature is 24°C If the tool life for the average cutting velocity of 90 m/min is measured as 10 min. and for a cutting velocity of 160 m/min is measured as 6 min. estimate the tool life when machining at: