great thankyou very much, how do you work out Nm^2 / c^2 are the SI units and what does Nm^2 actualy stand for, i am struggling to understand what a constant actualy is and how it is measured?
this is coulombs law and i als need to use the correct SI unts to represent A
F = force
Q1 = Charge 1
Q2 = Charge 2
A is the constant
and r2 is the sepeation