For the following matrix $$\left[ {\matrix{ 1 & { - 1} \cr 2 & 3 \cr } } \right]$$ the number of positive characteristic roots is

The composition of an oxy-acetylene flame for cutting of steel contain more oxygen.

In an orthogonal cutting operation,
The depth of cut $$=2$$ $$mm,$$
Width of cut $$=15$$ $$mm,$$
Cutting speed $$=0.5$$ $$m/s$$ and
The rake angle $$=0$$ deg.
The cutting force and the thrust force are respectively $$900$$ $$N$$ and $$600$$ $$N$$ and the shear angle $$=30$$ $$deg$$.

The average coefficient of friction between the chip and the tool is

In an orthogonal cutting operation, the cutting velocity is $$30$$ $$m/min$$ and the chip velocity $$15$$ $$m/min.$$ If the rake angle of the tool is $${10^0}$$.

The shear angle is