00:01
Let's first draw the electric force exerted by each source charge.
00:05
The electric force exerted by q1 should point away from q1 because same charges repel, so f1 should look like something like this.
00:18
And f2, exerted by q2, should point toward q2 because opposite charges attract.
00:27
And because q1 and q2 have the same max, so f2 should have the same length with qf1.
00:35
So f2 is like this.
00:39
And f3 should point toward q3.
00:45
And it's supposed to be longer than f1 and f2 because q3 have a larger magnitude.
00:54
So after we draw the direction of each electric force, we can calculate the magnitude of each direct, electric force.
01:03
And as we said, q1 and q2 have the same magnitude, so f1 should equal to f2, and they both equal to k times q times q over the square of their distance, which is 5 centimeter.
01:22
And we convert the numbers into the standard unit, and we'll get the result is 0 .72 times 10 to negative 5 newtons.
01:34
And that's for f1 and f2, and we can analyze the component of the sum of these two forces.
01:44
As we can see from this diagram, in the y direction, the f1 .y can sew out the f2y...