A cube shaped casting solidifies in $$5$$ min. The solidification time in min for a cube of the same material, which is $$8$$ times heavier than the original casting, will be

Water $$\left( {{C_p} = 4.18\,kJ/kg.K} \right)$$ at $${80^ \circ }C$$ enters a counter flow heat exchanger with a mass flow rate of $$0.5kg/s.$$ Air $$\left( {{C_p} = 1\,kJ/kg.\,K} \right)$$ enters at $${80^ \circ }C$$ with a mass flow rate $$2.09$$ $$kg/s.$$ If the effectiveness of the heat exchanger is $$0.8,$$ the $$LMTD$$ (in $$^ \circ C$$) is

Following data refers to an automat and a center lathe, which are being compared to machine a batch of parts in a manufacturing shop

Automat will be economical if the batch size exceeds

Details pertaining to an orthogonal metal cutting process are given below.

Chip thickness ratio $$0.4$$
Under formed thickness $$0.6mm$$
Rake angle $$ + {10^0}$$
Cutting speed $$2.5m/s$$
Mean thickness of primary shear zone $$25microns$$

The shear strain rate in $${s^{ - 1}}$$ during the process is