- #1
Kavorka
- 95
- 0
Homework Statement
According to statistical mechanics, the average kinetic energy of a particle at temperature T is 3kT/2, where k is the Boltzmann constant. What is the average de Broglie wavelength of nitrogen molecules at room temperature?
Homework Equations
KE = 3kt/2 = p2/2m
λ = h / p
The Attempt at a Solution
So p = (2KEm)1/2, and inserting KE = 3kt/2
p = (3kTm)1/2
And thus λ = h/p = h / (3kTm)1/2
The only problem I have is that it seems like the units don't work out.
Inserting the units only into h / (3kTm)1/2 :
(kg m2 /s2)/((m2 kg/s2 K)(K)(kg))1/2 =
(kg m2 /s2)/(m kg/s) =
m/s, not m
Am I simplifying the units wrong or is the equation wrong?