Okay say we know from magnetism. E = F / q F = KQq / R^2 Then we can say that. E = KQq / (R^2 / q) Then wouldn't we say E = KQq * q / R^2 E = KQq^2 / R^2 Its just like saying. 5 / (1 / 2) = 5 * 2 / 1 = 10. Why is it we cancel the q's instead of squaring them, because my textbook does that and ends up with this equation. E = KQ / R^2 Because the answers are different. Thanks.