Lag1989 task №8.10

The molecular beam falls on the wall at an angle α to its normal. The concentration of molecules in the beam is n, the mass of molecules is mo, and the velocity of each molecule is V. Molecules are reflected from the wall according to the law of an absolutely elastic impact. Find the pressure p experienced by the wall if: a) the wall is stationary; b) the wall moves in the direction of its normal with a speed u.