Brittle materials are machined with tools having zero or negative rake angles because it

In an orthogonal cutting test, the following observations were made
Cutting force $$=1200N ;$$ Thrust force $$=500N$$
Tool rake angle $$=zero ;$$ Cutting speed $$=1$$ $$m/s,$$
Depth of cut $$=0.8mm;$$
Chip thickness $$=1.5$$ $$mm$$

Chip speed along the tool rake face will be

In an orthogonal cutting test, the following observations were made
Cutting force $$=1200N ;$$ Thrust force $$=500N$$
Tool rake angle $$=zero ;$$ Cutting speed $$=1$$ $$m/s,$$
Depth of cut $$=0.8mm;$$
Chip thickness $$=1.5$$ $$mm$$

Friction angle during machining will be

The following data relate to an orthogonal turning process:
$$\,\,\,\,\,\,\,\,\,\,\,$$Back rake angle $$=15deg,$$
$$\,\,\,\,\,\,\,\,\,\,\,$$Width of cut $$=2mm,$$
$$\,\,\,\,\,\,\,\,\,\,\,$$Chip thickness $$=0.4mm,$$
$$\,\,\,\,\,\,\,\,\,\,\,$$Feed rate $$=0.2mm/rev.$$

The shear angle is