Assistance Needed For Rearranging Equations

[asad1]

Im currently studying A2 physics and I am doing potentials and electric fields etc. I've learned about Coulombs Law etc. and I am having difficulty rearranging the formulae.
For example take Coulombs Law. I had to rearrange it for Q2 and I spent ages just trying to rearrange it as I don't know how to do it properly. I used to just use the triangle or learn the expressions.

Could someone explain me how to arrange coulombs law for q2 or for R.

Thank You
Much appreciated.

 

[dave_baksh]

It's a sad indication of high school standards when an A2 student can't rearrange a simple equation. I've always been against the triangle method as it allows students to rearrange equations without understanding what's going on. I'm not blaming you - it's the failing of teachers and an increasingly skills based curriculum that reduces the time spent dealing with the maths of physics.

Anyway, to answer your question take a look at this youtube video -

That gives all the basics of rearranging equations and there are many more to be found.