# Gas Distribution

1. Dec 12, 2009

### nitefalls

1. The problem statement, all variables and given/known data

A planet has mass, 2 x 1022 kg, and radius, 2 x 106 m. Initially, its
atmosphere contains gas particles of various masses. If the gas is at temperature, 400 K,
and has a Maxwell-Boltzmann velocity distribution, what mass of particle will typically
escape from the planet’s gravitational pull? (Hint: You can just use the average velocity,
you don’t need to consider the full Maxwell-Boltzmann distribution).

2. Relevant equations
vrms=sqrt(3kbT/m)
P(v)=v^2*e^(-0.5mv^2/kbT)

3. The attempt at a solution

I have no clue at all

2. Dec 12, 2009

### nitefalls

wait i got it.. thx
the vrms was the escape velocity
hahaha XD

3. Dec 14, 2009

### cramster

Im having problems with this problem too can you tell me how you got it?

4. Dec 15, 2009

### esmeralda.ty

escape velocity v=sqrt2GM/ R
you need to use this velocity for maxwell-boltzmann speed distribution:
2GM/r= 3kT/m
you can find m from here.
I hope that helps