Five kg of nitrogen (N2) undergoes a process from p1 = 5 bar, T1 = 400 K to p2 = 2 bar, T2 = 750 K. Assuming ideal gas behavior, determine the change in entropy, in kJ/K, with: (a) constant specific heats evaluated at 450 K. (b) variable specific heats.

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.