00:01
All right, so let's say we have two objects, a and b, and they're both positively charged, but we're told the charge of a is twice the charge of b.
00:11
So we'll just call the charge of b.
00:12
We'll just call that q.
00:14
And so we're told that when they're placed a distance of 15 centimeters apart, they experience a force of 0 .5 to newton.
00:24
So we want to know what's the charge on each of the objects, or at least what's the charge on a? so first, we know the force is going to be kulams constant times the product of the two charges.
00:35
So this is 2q times q, right? so we can write that as 2 q squared.
00:40
And this is over r squared.
00:41
So we're solving for q.
00:42
So we can see it's the square root of f times r squared over 2k, but that's koulams constant.
00:49
So if we write that out, this is 0 .52 newton's times 0 .15 meters squared...