How are electric forces and distance related?

1 Answer
May 26, 2014

Electric forces are inversely proportional to the square of the distance from the source of the force.

Wow, what does that mean? In math it looks like this.

Electric Force = #(k_e*|q_1*q_2|)/(r^2)#

Where #r# is the distance between the charges, #q_1# and #q_2# are the magnitudes of the two point charges, and #k_e = 8.99\times 10^{9} N\cdot m^2/C^2#, is a constant of proportionality called the Coulomb constant. The equation above is a simplified version of Coulomb's Law; more specifically it is the scalar form.

In simpler terms, this means the force gets four times weaker every time you double the distance. This property is known as the Inverse-Square Law. A lot of different things in physics fallow this law. For more on this check out the link below.