# Homework Help: Fundemental Frequency units?

1. May 13, 2009

### jester07232

1. The problem statement, all variables and given/known data
The fundamental vibrational frequency of gaseous 14N16O is 1904 cm-1.

a. Calculate the force constant, using the simple harmonic oscillator model

2. Relevant equations

K=u((2pi)(v))^2 u=reduced mass

3. The attempt at a solution

u=[(14)(16)/(30)] (1kg/6.02e^26)= 1.24e^-26 Kg/molecules

K=(1.24e^-26 kg)((2pi)(1904 cm^-1))^2= 1.77e^-22 kg m^2

How do I get the answer in N/m ??

2. May 13, 2009

### Matterwave

What does it mean when there is a frequency given in cm-1? Frequency should be given in Hz (or per time of some sort). Perhaps instead of "fundamental frequency" they meant "wave number/vector"?

3. May 13, 2009

### jester07232

cm^-1 is the wavenumber.

4. May 13, 2009

### Matterwave

If you have K = u(2pi*v) why are you plugging in your wave number for v? v is a frequency yes? So how do you convert a wave number into frequency?

5. May 14, 2009

### jester07232

Ok...

Good point, I will change wave number to frequency.