What is the wind speed in m/s required to keep a great white shark suspended in midair during a summer day on the California beach?
Details and assumptions
Model the shark as a horizontal cylinder 6 m long and 1 m in diameter.
The air is at a pressure of 1 atm and a temperature of 30∘C.
The density of the shark is that of water, 1000 kg/m^3.
Assume that the wind gust that keeps the shark suspended is blowing straight upwards, and that the air molecules bounce off the shark elastically.
The acceleration of gravity is −9.8 m/s
^2.
ma, the molar mass of air, is 29 g/mol.