Automobile engines AND steam engines are examples of . a. internal combustion engines b. heat engines c. external combustion engines d. solar collectors

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.

Positive ions differ from neutral atoms in that