The tank shown below is being filled with a liquid through two separate inlets. Air (p = 0.00238 slug/ft and = 0.377 x 106 lbfs/ft) is trapped at the top of the tank. The height of liquid in the tank is h. The diameter of inlet (1) is 1 inch, the diameter of inlet (2) is 3 inches, and the average velocities of liquid entering inlets (1) and (2) are 3 ft/s and 2 ft/s, respectively. The tank has a constant cross- sectional area, At = 2 ft. (1) h air Tank area At liquid a) Calculate the rate of change in liquid height, dh/dt, at this instant. [6 marks] ANS: 0.0573 ft/s b) The height of the tank is 5 ft. If the air in the tank is at an absolute pressure of 14.7 pounds per square inch (psi) at time t = 0, when h = 3 ft, estimate the absolute pressure of the air 10 seconds later. Assume the temperature of the air remains constant and the velocities of liquid entering inlets (1) and (2) remain constant at 3 ft/s and 2 ft/s, respectively, over the 10 second time period. [6 marks] ANS: 20.6 psi