What is the formula/range for electromagnestism?

Please reply asap

You have to be much more specific here: there are many formulas that come to mind.

It starts with F(subscript em) = k ?

Are you speaking of coulomb attraction..

Force=kq1*q2/distance^2

Yes, you are correct! The formula you are referring to is Coulomb's Law, which calculates the force of attraction or repulsion between two charged particles. The formula is given by:

F = k * (q1 * q2) / distance^2

Here, F represents the electrostatic force, q1 and q2 are the magnitudes of the charges of the two particles, and the distance^2 is the square of the distance between them. The constant k is known as the electrostatic constant, and its value depends on the units being used.

Therefore, using this formula, you can calculate the electromagnetic force between two charged particles based on their charge magnitudes and the distance between them.