Solution Found!
CP (a) Compute the increase in gravitational potential
Chapter 18, Problem 72P(choose chapter or problem)
CP (a) Compute the increase in gravitational potential energy for a nitrogen molecule (molar mass 28.0 g/mol) for an increase in elevation of 400 m near the earth’s surface. (b) At what temperature is this equal to the average kinetic energy of a nitrogen molecule? (c) Is it possible that a nitrogen molecule near sea level where T = 15.0o C could rise to an altitude of 400 m? Is it likely that it could do so without hitting any other molecules along the way? Explain.
Questions & Answers
QUESTION:
CP (a) Compute the increase in gravitational potential energy for a nitrogen molecule (molar mass 28.0 g/mol) for an increase in elevation of 400 m near the earth’s surface. (b) At what temperature is this equal to the average kinetic energy of a nitrogen molecule? (c) Is it possible that a nitrogen molecule near sea level where T = 15.0o C could rise to an altitude of 400 m? Is it likely that it could do so without hitting any other molecules along the way? Explain.
ANSWER:Solution 72P Step 1 3 The molar mass of N ga2is M = 28.0 g/mol = 28.0 × 10 kg/mol 23 And the avogadro number is N = 6.0A × 10 /mol So, the mass of one molecule is 3 28.0×10 kg/mol 26 m = 6.02×103/mol = 4.65 × 10 kg Now the potential energy at a height h is given by E p mgh = (4.65 × 10 26 kg)(400 m)(9.8 m/s ) = 1.82 × 10 22J