Question

Most of the wind associated with a thunderstorm is caused by parcels of air, called air masses, that fall down due to gravity (which is called a down draft). a) Assuming that the air mass falls down from the top of a thunderstorm which is 12 km above the ground, how fast is the air mass traveling when it reaches the ground? b) Is this speed reasonable

Answer 1

a) We have:

$$\rho gh=0.5\rho v^2$$

$$v=\sqrt{2gh}=\sqrt{2(9.8)(12000)}=485\frac{m}{s}$$

b) No.