# What does this symbol do?

Discussion in 'Math' started by Sparky49, Apr 10, 2012.

1. ### Sparky49 Thread Starter Well-Known Member

Jul 16, 2011
835
417
Hi everyone,

I'm on a train using my phone, so apologies if this seems blunt.

I'm looking at Coulombs law, but I don't understand part of it when the denominator is r squared.

The r on the numerator has a squiggle above, which I do not understand.

Similar to the r in the vector form equation here;
http://en.m.wikipedia.org/wiki/Coulomb's_law#section_1

Thanks,

Sparky

2. ### DerStrom8 Well-Known Member

Feb 20, 2011
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1,329
Well, I think you pretty much answered your own question about the R with the "squiggle". It's actually called a circumflex, and it denotes a unit vector. People would often read it as R(hat) or R-hat. It is the same as r-r1.

The d^2 in the denominator means that charge is inversely proportional to the distance squared.

Sparky49 likes this.
3. ### Sparky49 Thread Starter Well-Known Member

Jul 16, 2011
835
417
Thanks. V ety much. Gtov go losing signAL lol.