Understanding the Relationship Between r & $\hat{r}$ in a Vector Equation

  • Context: Graduate 
  • Thread starter Thread starter Astrum
  • Start date Start date
  • Tags Tags
    Relationship Vector
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 2K views
Astrum
Messages
269
Reaction score
5
I'm not sure I get how:[tex]\frac{\mu_{0}}{4\pi}\int_{C}\frac{I(d\vec{l}\times\vec{r})}{r^{3}}[/tex] = [tex]\frac{\mu_{0}}{4\pi}\int_{C}\frac{I(d\vec{l}\times\hat{r})}{r^{2}}[/tex]

the r is a displacement vector in the first, and in the second it's a unit vector, but why is this so?
 
Last edited:
Physics news on Phys.org
The second expression is correct, the first one is not.
 
Sorry, meant to put a cubed there. Fixed
 
There's nothing really to get: [itex]\widehat{r} = \frac{ \vec{r} }{r}[/itex].
 
I see,another dumb question I asked, sorry for wasting your time...