00:01
In this problem, we have two charges.
00:02
So charge one will be five coulums.
00:06
And the second charge we're given.
00:07
I'm just going to call it charge two is 15 couloms.
00:09
And we're trying to figure out how far apart they are if they have an electrical force between them or force of electrical attraction of 6 .75 times 10 to the 13 newtons.
00:23
And we know since this is a positive force, they're actually going to be repelling each other.
00:26
And so we're going to use the electrical force.
00:30
Force equation, which is the coulum's constant, charge one, charge two, all over the distance between them squared.
00:40
So let's rearrange this equation before we start putting numbers in, because these numbers do get really large, and so it's best just to rearrange your equation first.
00:49
So multiply both sides by radius squared, or the distance between the two objects squared, and those will cancel out.
00:55
So then we have force times the distance between the charges squared is equal to cumulam's constant charge one charge two now divide both sides by force to move that to the other side and so that leaves this r squared is equal to k q1 q2 over f e well how do we get rid of this square you take the square root of both sides and so now we have r it's equal to the square root we'll make this large of k q1 q2 all over f e and so now it's just a one step probably just plug them in well we don't aren't giving k but k is a constant this number never changes and different instructors do use different um number so it they might use 8 .9 or 8 .98 typically it's rounded to 9 times 10 to the 9 newtons so just make sure you're using whatever you're expected to use in class.
01:58
So now we have all our values, all these values can be plugged into our equation down here...