how do you solve E=kq/r^2 Solve for r

Question

I dont know how to solve for the indicated variable for r squared

Answer 1

Here are the general steps:

 

1) Clear the denominators by multiplying both sides by LCD.

2) Solve for the indicated variable.

 

r²E = kq  ⇒  r² = kq/E  ⇒  r = ±√(kq/E).

 

If you know in advance that r must be positive, you can omit the ± safely.