00:01
Okay, so scientists have created electric and magnetic fields as shown in the figure from your problem.
00:08
These fields are also seen by scientists that zoom pass in a rocket traveling in the x direction.
00:15
So the velocity in the x direction is 1 times 10 to the 6th in units of meters per second.
00:23
We know that the magnitude of the magnetic field is 0 .48 tesla and the magnitude of the electric field is 1 .2, 10 to the 6 in units of volts per meter.
00:38
And we need to find the angle that it's going to make.
00:43
So start with the net electric field.
00:47
E net is equal to e plus v cross b in the j hat direction, since you have a magnetic field.
00:59
So e plus v cross b.
01:04
This is e cosine of theta in the i -hat direction, minus e sine of theta in the j -hat direction.
01:13
So that's just the components of e.
01:15
And then v -cross -b is v times b in the j -hat direction.
01:24
They told you that the angle is 45 given from the figure.
01:28
So i'm just going to go ahead and sub that in.
01:32
45 degrees, 45 degrees.
01:39
And then let's combine components.
01:42
So this is e cosine of 45 degrees in the i -hat direction.
01:49
And then vb minus e sign of 45 degrees.
01:54
All of this is in the j -hat direction.
01:57
We need that because theta is equal to the inverse tangent of whatever is in the y direction over whatever is in the x direction...