00:01
Okay, in this question, we're talking about magnetic field created by a moving charge.
00:06
So in this situation, we have a proton, which is a distance of 6 .6 micrometers from point b, which is where we're going to measure the magnetic field.
00:16
And the proton is moving at the speed of 3 .3 times 103 meters per second.
00:22
And, of course, the charge of the proton is going to be e.
00:26
And in question a, they ask us, what is the direction? of r hat.
00:36
And we know that r hat is the direction from the charge to the point where we are measuring the magnetic field.
00:44
So this is going to be our our vector and so our hat is just in that direction with a magnitude of one.
00:53
Okay, and then in question b, we're told that the velocity of the proton is horizontal...