# Relation between mass and wavelength

1. Aug 2, 2010

### Misr

Hi,
Why are mass and wavelength are inversely proportional?

2. Aug 3, 2010

### Dr Lots-o'watts

Are you refering to de Broglie's matter waves?

As Hawking said, physics' job is to ask how.

But briefly, interference effects can be observed with electron beams, but not with marbles, and the shorter the wavelength of anything, the more it acts like a particle.

3. Aug 13, 2010

### Misr

ok I change my question .."how are mass and wavelength are inversely proportional? "

4. Aug 13, 2010

### diazona

$$\lambda = \frac{h}{p}$$

5. Aug 15, 2010

### Misr

Looks very helpful but what is "h" and what is "p" ?

6. Aug 15, 2010

### Dickfore

h is a fundamental constant of nature and

$$p = \frac{m \, v}{\sqrt{1 - v^{2}/c^{2}}}$$

is the momentum of a particle with mass m moving at speed v and c is the limit speed with which any interaction can be transmitted and is another fundamental constant of nature.

7. Aug 15, 2010

### Misr

oh ok got it Thanks very much