A pitot tube Fig. is used to determine the air speed of an airplane. It consists of an outer tube with a number of small holes B (four are shown that allow air into the tube, that tube is connected to one arm of a U-tube. The other arm of the U-tube is connected to hole A at the front end of the device, which points in the direction the plane is headed. At A the air becomes stagnant so that `v_(A)` = 0. At B, however, the speed of the air presumably equals the airspeed v of the plane. (a) Use Bernoulli's equation to show that
`v = sqrt((2rho gh)/(rho_(air)))`
where `rho` is the density of the liquid in the U-tube and his the difference in the liquid levels in that tube. (b) Suppose that the tube contains alcohol and the level difference h is 20.0 cm. What is the plane's speed relative to the air? The density of the air is `1.03 kg//m^(3)` and that of alcohol is 810 kg/`m^(3)`

Explanation

55.5 m/s