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 a single pass rolling process using $$410mm$$ diameter steel rollers, a strip of width $$140mm$$ and thickness $$8mm$$ undergoes $$10\% $$ reduction of thickness. The angle of bite in radians is

In a single pass rolling operation, a $$20mm$$ thick plate with plate width of $$100mm$$, is reduced to $$18mm$$ thick. The roller radius is $$250mm$$ and rotational speed is $$10$$ $$rpm.$$ The average flow stress for the plate material is $$300$$ $$MPa.$$ The power required for the rolling operation in $$kW$$ is closer to

In open die forging, a disc of diameter $$200mm$$ height $$60mm$$ is compressed without any barreling effect. The final diameter of the disc is $$400mm.$$ The true strain is