A13-m^3 rigid tank contains nitrogen at 17°c and 600 kpa. some nitrogen is allowed to escape until the pressure in the tank drops to 400 kpa. if the temperature at this point is 15°c, determine the amount of nitrogen (kg) that has escaped.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?