# Homework Help: Frequence and wavenumbers

1. Jun 16, 2006

### asdf1

if frequency is (1/sec), then why is wavenumber (1/cm) considered a unit of frequency?

2. Jun 16, 2006

### Hootenanny

Staff Emeritus
It is considered the spatial representation of frequency, it in itself is not a fequency. However, you can obtain the the wavenumber by dividing the frequency by the speed of light. Observe,

$$c = f\lambda \Leftrightarrow \frac{1}{\lambda} = \frac{f}{c}$$

$$\frac{1}{\lambda}\propto f$$

3. Jun 19, 2006

### asdf1

wow! never thought of it that way before~ thank you!!!