Two monatomic ideal gases are in thermal equilibrium with ea

1. Nov 4, 2016

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1. The problem statement, all variables and given/known data
Two monatomic ideal gases are in thermal equilibrium with each other. Gas A is composed of molecules with mass m while gas B is composed of molecules with mass 4m. The ratio of the average translational kinetic energies KA/KB is:

2. Relevant equations
KE=0.5xmxVavarage^2
ATTEMPTS:]
KE!/KE2 all are constants except m then it will be 1/4
but the correct answer is one why?

2. Nov 4, 2016

phyzguy

What is temperature? What does it mean to be in thermal equilibrium?

3. Nov 4, 2016

Any Help

it means delta T=0 then delta Einternal=0

4. Nov 4, 2016

5. Nov 4, 2016

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Temperature is a measurement of how heat or cold an object is. It reflects the delta internal energy where the change in temprature will cause a change in internal energy.
Is that what you mean?

6. Nov 4, 2016

phyzguy

From the Wikipedia article on temperature:

"The kinetic theory offers a valuable but limited account of the behavior of the materials of macroscopic bodies, especially of fluids. It indicates the absolute temperature as proportional to the average kinetic energy of the random microscopic motions of those of their constituent microscopic particles, such as electrons, atoms, and molecules, that move freely within the material."

7. Nov 4, 2016

Any Help

okay, but also its proportional to mass

8. Nov 4, 2016

phyzguy

No! It's not! Temperature is proportional to the average kinetic energy of the constituent particles. So if two gases have equal temperatures, they have equal average kinetic energies. So the heavier particles are moving slower.

9. Nov 4, 2016

Any Help

ah okay I got your point thanks