A shaft of 80mm diameter transmits power at maximum shear stress of 63MPa. Find the length of a 20mm wide key required to mount a pulley on the shaft so that the stress in the key does not exceed 42MPa.​

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false