I'm trying to find the relationship between electric field strength and distance from point charge as an equation. I found the equation cd = E/(c*c).

c is the factor by which the distance changes and E is the field strength. Is the equation good enough?

The equation you mentioned, cd = E/(c*c), does not represent the relationship between electric field strength and distance from a point charge accurately. The correct equation is given by Coulomb's law, which states that the electric field strength (E) at a distance (d) from a point charge (Q) is given by the equation:

E = k|Q|/d^2

In this equation, k represents the electrostatic constant and has a value of approximately 9 x 10^9 N·m^2/C^2. The absolute value of the charge (|Q|) signifies the magnitude of the charge.

To find the relationship between electric field strength and distance, we can derive it from Coulomb's law. Dividing both sides of the equation by |Q| will give us:

E/|Q| = k/d^2

Now, we can see that E/|Q| is a constant, since k and the magnitude of charge remain constant for a given system. Therefore, we can rewrite the equation as:

E ∝ 1/d^2

This expression indicates that electric field strength is inversely proportional to the square of the distance from the point charge.