A cylinder 8 in. in diameter and 3 ft long is concentric with a pipe of 8.25 in internal diameter. Between the cylinder and the pipe there is an oil film. What force is required to move the cylinder along the pipe at a constant velocity of 3 ft/s? The kinematic viscosity of the oil is 0.006 ft2 /s; the SG is 0.92.

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2