
Well let's plug into this equation.

When we carry out this multiplication, we get a result of 1.35 x10¹⁰ J.

Now notice that this is a negative number and in fact, if r were smaller,

so these were closer together, it would have been a more negative number.

It would have been a lower potential energy.

Now in genuine physics, objects like to be in a low energy state.

Balls like to roll downhill and positive charges like to be with negative charges.

And we can see in this equation that if one charge is positive and the other negative,

well this energy will be negative, and this r want to be as small as it possibly can.