試題詳解

22. Consider a thin horizontal layer of the atmosphere, of thickness dy, of area A, with pressure P at the om. This layer contains ny molecules per unit volume with an average mass m p and is under the influence of gravity with gravitational acceleration g. What is the magnitude, dP, of the pressure difference between the top and bottom of the layer?
(A) mgdy.
(B) mgnydy.
(C) mgAdy.
(D) mgnvAdy.
(E)mgnvAPdy.