Problem 3-1.(5pts) Apiston-cylinder device contains 2 ft3of airinitially at 200 lbf/in2and 450oF. A linear spring which has a spring constant of 10 kN/m is attached to the 1-ft diameter piston and it is initially undeformed. This device is now cooled until the volume is one-half its original size. Calculate (a) the total exergy destroyed, and (b) the second law efficiency.

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_