Solve for $$y$$ if $${{{d^2}y} \over {d{t^2}}} + 2{{dy} \over {dt}} + y = 0$$ with $$y(0)=1$$ and $${y^1}\left( 0 \right) = - 2$$

The value of the following determinant $$\left[ {\matrix{ 1 & 4 & 9 \cr 4 & 9 & {16} \cr 9 & {16} & {25} \cr } } \right]$$ is

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

Parting-off operation is carried out on a cylindrical work-piece of $$100mm$$ diameter. The groove width is $$2$$ $$mm$$ and an in feed of $$0.2$$ $$mm$$ per revolution is given at a maximum cutting speed of $$60$$ $$m/mm.$$ The specific cutting force for the material is $$800\,\,N/m{m^2}.$$

The tangential force on the tool is