Ch19.39 At what temperature does the rms speed of (a) H 2 (molecular hydrogen) a
ID: 1310632 • Letter: C
Question
Ch19.39
At what temperature does the rms speed of (a) H2 (molecular hydrogen) and (b) O2 (molecular oxygen) equal the escape speed from Earth? At what temperature does the rms speed of (c) H2 and (d) O2 equal the escape speed from the Moon (where the gravitational acceleration at the surface has magnitude 0.160g)? Considering the answers to parts (a) and (b), should there be much (e) hydrogen and (f) oxygen high in Earth's upper atmosphere, where the temperature is about 1000 K (if yes, then type 1. If no, then type 2)? Earth radius is 6.37
Explanation / Answer
KE = (3/2)kT and KE = (1/2)mv^2
(3/2)kT = (1/2)mv^2
solve for T with appropriate escape velocities and particle masses (k is Boltzmanns constant)