A metal rod of initial length $${L_0}$$ is subjected to a drawing process. The length of the rod at any instant is given by the expression, $$L\left( t \right) = {L_0}\left( {1 + {t^2}} \right),$$ where $$t$$ is the time in minutes. The true strain rate (in $${\min ^{ - 1}}$$) at the end of one minute is _____________

In solid-state welding, the contamination layers between the surfaces to be welded are removed by

If the Taylor's tool life exponent $$n$$ is $$0.2,$$ and the tool changing time is $$1.5$$ $$min,$$ then the tool life (in min) for maximum production rate is ____________

The main cutting force acting on a tool during the turning (orthogonal cutting) operation of a metal is $$400N.$$ The turning was performed using $$2mm$$ depth of cut and $$0.1mm/rev$$ feed rate. The specific cutting pressure (in $$N/m{m^2}$$ is