# How is mass density affected by speeds near c?

1. Nov 12, 2009

### elliottmarter

basically what is the relationship between mass density at "zero" speed and mass density at speeds nearing the speed of light (0.98c,0.99c etc)

in the form M = $$\gamma$$ Mo if possible

Thanks a lot guys!

2. Nov 12, 2009

### elliottmarter

sorry just saw that this should have gone in the H/W section :uhh:

3. Nov 12, 2009

### A.T.

4. Nov 12, 2009

### elliottmarter

well, i mean i took a guess that it takes that form, but is gamma squared or cubed?...anything that could change the proportionality...you know :)

cheers

5. Nov 12, 2009

### A.T.

If by "mass density" you mean "relativistic mass / volume" then yes, gamma is squared:

gamma = 2 means that a moving object has half the volume, but also double relativistic mass, so 4 time more "mass density".

6. Nov 12, 2009

### elliottmarter

ah i see!

thanks a lot, i think i will be frequenting these forums often in the future