The feasibility of a one-passenger VTOL (vertical takeoff and landing) craft is under re...

The feasibility of a one-passenger VTOL (vertical takeoff and landing) craft is under review. The preliminary design calls for a small engine with a high power-to-weight ratio driving an air pump that draws in air through the 70° ducts with an inlet velocity v = 40 m/s at a static gage pressure of -1.8 kPa across the inlet areas totaling 0.1320 m². The air is exhausted vertically down with a velocity u = 420 m/s. For a 90-kg passenger, calculate the maximum net mass m of the machine for which it can take off and hover. (See Table D/1 for air density.)