00:01
The force is attractive in this problem, which means that q2 is positive for the force to be attractive, since, like, charges repel.
00:11
And so, we're going to use the equation, f is equal to k, q1, q2, over r squared.
00:21
And we're going to solve for the unknown, which is q2 here.
00:25
When we do that, we get q2 is equal to f, r squared, since i multiply three by r squared, to get up.
00:34
Numerator divided by k q1 at this point we can start plugging in all the stuff the problem gives us because the problem gives us all this information here we know the force is 0 .2 newtons the distance is 0 .3 meters and that's going to be squared k is 8 .99 newton meters squared over kulam squared and the absolute value of q1 is equal to 0 .55 times 10 to the minus 6.
01:13
Notice that this is now positive because of the absolute value.
01:19
And so we see that the coulum is going to cancel with one of these columns here.
01:25
The meter squared will cancel the meter squared there and the nudes will cancel the nons.
01:28
And so we'll be left with a coolum in the numerator, which is good because we're solving for a charge.
01:34
As far as the numbers go, you should get 3 .64 times 10 to the negative 6...