Problem 3:
find the amount of power that is delivered to a load at 1 = 3ms if the current entering the
positive terminal is given by the following expression for current:
i=5cos60pit
with voltages given by the expression (a) v = 3i and (b) v = 3di/dt

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.

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