Rms speed of Hydrogen atoms in space

AI Thread Summary
The discussion focuses on calculating the root mean square (rms) speed of hydrogen atoms in outer space, where the density is approximately one atom per cm³ and the temperature is around 2.7 K. The equation PV = NkT is referenced, but the user is uncertain about how to determine the volume needed for the calculation. The equipartition theorem is mentioned, indicating that hydrogen atoms possess kinetic energy related to their temperature and degrees of freedom. The user seeks clarification on what mass to use for hydrogen atoms in their calculations. Overall, the thread revolves around applying thermodynamic principles to find the rms speed and pressure of hydrogen in space.
notsam
Messages
50
Reaction score
0

Homework Statement

In outer space the density of matter is about one atom per cm^3, mainly hydrogen atoms , and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).



Homework Equations

PV = NkT




The Attempt at a Solution

So by using PV = NkT, I have all the variables except the volume. Or am I way off using this equation.
 
Physics news on Phys.org
Have you encountered the equipartition theorem before? According to the theorem, hydrogen atoms have a kinetic energy of 3/2kT, because they have 3 degrees of freedom.
 
Ok...so 1/2(mv^2)=3/2kT. But what do I use for mass?
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »

Similar threads

RMS speed of Hydrogen Atoms in space
Replies
1
Views
8K
Help with rms speed of gas when molecules are doubled
Replies
1
Views
5K
Calculating RMS Speed of Helium & Oxygen Gas at 260K
Replies
6
Views
5K
Atomic Structure problem regarding interatomic spacing
Replies
13
Views
2K
Leakage of Air in a Spacecraft
Replies
16
Views
1K
Calculating Pressure of a Dilute Gas in Space
Replies
4
Views
1K
Fnding the rms speed of hydrogen
Replies
3
Views
12K
Calculating Final Speed in Elastic Collision: Uranium Atom and Hydrogen Molecule
Replies
1
Views
1K
Calculating Hydrogen Mass from Ideal Gas Law
Replies
3
Views
4K
Rms velocity of electron in free space?
Replies
2
Views
5K

Hot Threads

Recent Insights

Back
Top