00:01
In this problem we have two particles, a small q1 and a small q2.
00:07
And we want to compute what is the electric field that these two particles produce at these two points along the x -exis.
00:19
And we also know where these particles are.
00:24
Okay, so the equation that we are going to need in order to solve this problem is this equation here.
00:30
Says that the magnitude of the electric field is just the column constant, that is this k, that has this numericol value, multiplying the absolute value of the electric charge of the particle and divided by the distance square.
00:48
So, for instance, if we want to compute the electric field at the point x equal to zero, okay, so at this point here, we will have the contribution of these two particles.
01:06
So first for the first particle, this is k1.
01:11
This would be just the k constant, the column constant, that is 9, 10 to the 9, newton, meter squared divided by column square.
01:22
Multiplying the absolute value of this electric charge, that is 8 .94 column, and all of that this is divided by the distance, this distance here.
01:37
So this distance is 0 .03 square in mirrors, okay? and now we need to check what is the direction of the electric field.
01:53
So we know that when we have a positive electric charge, the electric field that is produced by this charge points out of the charge.
02:04
So if this is positive, the electric field that produced has this direction here.
02:10
This is for charge 1.
02:13
So we're going to use a negative sign here that symbolize that this electric field points in the opposite direction to the positive direction of the x -exes.
02:27
So this is the contribution for the first charge.
02:31
Now we're going to compute the contribution of this q2.
02:34
So this again we need the column constant multiplying the absolute value of this electric charge that is 25 .2 and all of this is divided by the distance.
02:55
So now the distance is this distance between the particle and the point where we want to compute the electric field.
03:05
So it's all this distance here.
03:08
So this distance is .09.
03:12
Mirrors, this is a square, this is also column, okay? and now let's see the direction.
03:19
This is a negative particle, a negative charge.
03:23
So when the charge is negative, the electric field points to the particle.
03:29
So it's the opposite as when the particle is positive.
03:34
So in this case, the electric field has this direction here, because the charge is negative.
03:42
Okay, so we're going to symbolize this direction that is the same direction as the x -exes as a positive.
03:50
So we're going to use here a plus sign...