Intro to Gas Dynamics Problem, please help

11. Consider an air puck, shaped like an upside-down bowl with a hole cut out the center, with a 15" diameter shell and an air intake hole 5" in diameter at the top of the puck. To generate lift, an 8W motor with 76% efficiency (76% of the 8W electrical input goes toward work) drives a fan mounted at the central hole. That is, all airflow coming in passes through the fan. The flow exits around the air puck perimeter through a small gap between it and the ground. You may consider the flow to be steady, incompressible, and adiabatic without external forces. (a) Determine the velocity of the flow exiting the shroud and the height above the ground the puck must sit when the mass flow rate is 150 g/s. (b) Under these conditions the pressure differential over the ground surface is de- scribed by the function p(r) - po = 50Pa (1 -(r/ R)?) for r R where po is the ambient pressure. Determine the total pressure force below the puck. (c) Using y-momentum balance, determine the total mass of the puck that can be supported under these conditions