00:01
So in this question, we have two waves and they generate a standing wave.
00:04
A string applies 3 meters, and it produces 3 loop standing wave, so n equals 3, and it looks something like this.
00:14
And the wave speed, v, is 100 meters per second.
00:19
Okay, so the 3 is n.
00:23
We also know the amplitude, the amplitude ym equals 1 centimeter.
00:31
Okay, so there are a couple of things we need to find.
00:33
We need to a look for ym.
00:36
Well, that's just an amplitude.
00:37
We're told that.
00:40
But we're told that for the superposition of two waves.
00:49
Now we want to figure out what's the amplitude for one of the waves.
00:53
And so that's ym.
00:56
Then b, we want to look for k.
00:58
C, we want to look for omega.
01:01
And finally, we want to look for the sign in front of omega.
01:06
So that is a weird question.
01:09
So sign in front of omega, because we know standing waves always have two waves traveling opposite direction.
01:18
So of course, one side will be positive, one side will be negative.
01:22
But let's first take a look.
01:26
We have part a.
01:29
So for standing waves, we always have one wave that's sine kx plus omega t times y...