Relation between kinetic energy and temperature


by johnathon
Tags: energy, kinetic, relation, temperature
johnathon
johnathon is offline
#1
Apr1-12, 07:11 AM
P: 40
Where does the 3/2 come from?
[tex]\frac{1}{2} mv^2 = \frac{3}{2} kT [/tex]
Phys.Org News Partner Physics news on Phys.org
Physicists consider implications of recent revelations about the universe's first light
Vacuum ultraviolet lamp of the future created in Japan
Grasp of SQUIDs dynamics facilitates eavesdropping
sophiecentaur
sophiecentaur is offline
#2
Apr1-12, 07:26 AM
Sci Advisor
PF Gold
sophiecentaur's Avatar
P: 11,378
A particle can move in any of three directions (that's where the 3 comes from), with kt/2 being the kinetic energy carried by motion on each the x,y or z dimensions.
This link gives a short and sweet bit of book work. That Hyperphysics site is good for many things, actually.
Doc Al
Doc Al is offline
#3
Apr1-12, 07:28 AM
Mentor
Doc Al's Avatar
P: 40,905
Quote Quote by johnathon View Post
Where does the 3/2 come from?
[tex]\frac{1}{2} mv^2 = \frac{3}{2} kT [/tex]
There are three translational degrees of freedom, each contributing 1/2kt to the total energy. This from the equipartition theorem.

Dadface
Dadface is online now
#4
Apr1-12, 08:01 AM
PF Gold
Dadface's Avatar
P: 2,004

Relation between kinetic energy and temperature


Taking it back a step the 3kT/2 can be found by equating the two ideal gas equations,one being obtained experimentally(PV=RT) the other being obtained theoretically using kinetic theory(PV=Nmc bar squared/3)


Register to reply

Related Discussions
Relation between stopping distance and Kinetic Energy Introductory Physics Homework 3
Relation between kinetic energy and temperature General Physics 2
Relation for Kinetic energy and the lorentz factor. Advanced Physics Homework 3
Kinetic Energy in relation to the ideal gas law General Physics 1
Relation Between Inertia And Kinetic Energy Question Classical Physics 2