00:01
In this question, we are told there are two equally charged particles moving at each other perpendicular to a uniform magnetic field.
00:11
And so first we'll draw a little picture.
00:14
We'll say magnetic field b is going into page, which we denote by these little xs.
00:24
And then if we have two charges that are both the same, we'll say here's one, here's the other, and this one's moving this way, this one's moving this way, and they both have charged.
00:46
So this is before they collide.
00:49
So first we can write out the force on a particle due to a magnetic field, fb, is equal to qv cross b.
01:02
But in this case, since they're moving with a velocity perpendicular to the magnetic field, this simply becomes qvv.
01:13
And using our right -hand rule, we can see that force on the top particle moving down qv cross b.
01:22
So the force would be going this way on this particle.
01:28
And qv cross -b with this one.
01:31
This will be the force here.
01:33
So this is before they collide...