00:01
All right, we're talking about electromagnetic waves, and we want to evaluate the truth of several of these statements.
00:06
So choice a tells us that electromagnetic waves cannot travel through solid objects.
00:11
So this is not true because this happens all the time, like, you know, electromagnetic waves travel through your body, for instance, because x -rays are electromagnetic waves, for instance.
00:21
And if you've ever been to the doctor's office, you know that, you know, you have to wear this lead shielding to protect yourself from x -rays because otherwise they'll go through you.
00:30
Go into your body anyway and potentially out of your body as well um so if you think about the truth of that statement just consider the fact that x -rays are electromagnetic waves and that actually helps us with a later statement so b says an electromagnetic wave is a transverse wave so this would be true because a transverse wave is a wave where the oscillation is perpendicular to the direction of motion so if i have a wave, i'll draw it in green, that is maybe propagating this way, then that means that the oscillation takes place at right angles this, right? it's going up and down, oscillation is, where it's traveling to the right.
01:12
So those would be at 90 degrees angle.
01:14
So this is true for an electromagnetic wave.
01:17
Next up, we got only visible light as an electromagnetic wave.
01:20
So this is false because there are all sorts of forms of light.
01:24
The x -rays we already mentioned, but we have also what are called gamma rays.
01:30
That's one consideration.
01:33
You have infrared light, you know, like the light emitted from your body heat.
01:39
We have radio waves.
01:41
We have microwaves.
01:44
There's all sorts of light outside of just what we can see, what is visible.
01:49
Sorry, this radio looks a little.
01:50
There we go.
01:52
Next up, an electromagnetic wave is composed of a constant magnetic field that is perpendicular to an oscillating electric field...