Sarthaks Test
0 votes
in Physics by (8.6k points)

(a) Pressure decreases as one ascends the atmosphere. If the density of air is ρ, what is the change in pressure dp over a differential height dh?

(b) Considering the pressure p to be proportional to the density, find the pressure p at a height h if the pressure on the surface of the earth is p0

(c) If p0 = 1.03×105 N m–2, ρ0 = 1.29 kg m–3 and g = 9.8 m s–2, at what height will the pressure drop to (1/10) the value at the surface of the earth? 

(d) This model of the atmosphere works for relatively small distances. Identify the underlying assumption that limits the model.

1 Answer

0 votes
by (13.6k points)
selected by
Best answer

(a) Consider a horizontal parcel of air with cross section A and height dh. Let the pressure on the top surface and bottom surface be p and p+dp. If the parcel is in equilibrium, then the net upward force must be balanced by the weight.

(b) Let the density of air on the earth’s surface be ro , then

(d) The assumption p  r is valid only for the isothermal case which is only valid for small distances.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.