A standard machine tool and an automatic machine tool are being compared for the production of a component. Following data refers to the two machines.

The breakeven production batch size above which the automatic machine tool will be economical to use, will be

In an orthogonal cutting test on mild steel, the following data were obtained
Cutting speed: $$40$$ $$m/min,$$
Depth of cut: $$0.3$$ $$mm,$$
Tool rake angle : $$ + {5^ \circ },$$
Chip thickness: $$1.5$$ $$mm,$$
Cutting force: $$900$$ $$N,$$
Thrust force: $$450$$ $$N$$
Using Merchant's analysis, the Friction angle during the machining will be

A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $$200rpm$$. The axial feed rate is $$0.25$$ $$mm$$ per revolution. Depth of cut is $$0.4mm.$$ The rake angle is $${10^ \circ }.$$ In the analysis it is found that the shear angle is $${27.75^ \circ },$$

The thickness of the produced chip is

A cylinder is turned on a lathe with orthogonal machining principle. Spindle rotates at $$200rpm$$. The axial feed rate is $$0.25$$ $$mm$$ per revolution. Depth of cut is $$0.4mm.$$ The rake angle is $${10^ \circ }.$$ In the analysis it is found that the shear angle is $${27.75^ \circ },$$

In the above problem, the coefficient of friction at the chip tool interface obtained using Earnest and Merchant theory is