# Maxwell - Boltzman distribution

1. Sep 1, 2013

### mattT1227

I made a spreadsheet to plot the 3d speed distribution from the MB probability function. It matches the peak and fall-off of published graphs. I then tried to integrate it by summing over interval widths times probability. I thought the area should be 1. My result is around 5 or 6. I've tried really small intervals, around 0.25 m/s, that didn't help. Must be I don't understand what the area under the probability curve represents.

2. Sep 1, 2013

### SteamKing

Staff Emeritus
http://en.wikipedia.org/wiki/Maxwell–Boltzmann_distribution

It gives properties of the M-B distribution, including the PDF and corresponding CDF. You must have made an error in your calculations.

3. Sep 2, 2013

4. Sep 2, 2013

### mattT1227

Thanks all. Problem solved. Area under curve is 0.98 by numerical integration, close enough.