# Spacial Velocity?

1. Feb 6, 2009

### Reedeegi

I was doing some homework for GR when I came across the term "spacial velocity." What is its definition?

It's in the context of finding the spacial velocity using the knowledge of the four-velocity U being U = (1+t^2,t^2,t√2,0) [I don't need help with the problem itself, I just need to know the definition in this context]

2. Feb 6, 2009

### Fredrik

Staff Emeritus
Check out this post. They must be talking about the 3-vector I call $\vec v$. (Note that I'm using units such that c=1).

Oh yeah, and it's spelled "spatial".

Hm, maybe not. Dictionary.com says that "spacial" is OK too.

Last edited: Feb 6, 2009