00:01
16 .34.
00:02
So we have a wave with the given properties here that's propagating along a cord that has these properties here.
00:13
It's a density and tension.
00:17
So first of all we want to find basically what the p average is, which in this case it expresses it as the average rate rate at which energy is transported by the wave to the opposite end of the cord.
00:30
And then we would want to imagine if we have a string that's adjacent to it and they're both like sort of fixed to the same thing, but there's two of them.
00:43
You know, what's the power that's being transmitted over to here by the identical wave on the other string plus our original one? and then if they're both on the same string, we want to figure out what the power is for various phase differences.
01:03
So the first thing that we're going to want to just go ahead and figure out right off the start is the wave speed.
01:21
This is 775 meters per second because that that saves us the bother of having to, you know, do some sort of, you know, algebraic substitution stuff in our expression for the average power, which is one -half times the density.
01:49
Times the wave speed, times the angular frequency squared, times the amplitude squared.
02:02
So this is 10 watts in our first case.
02:08
In the second case, we don't have any sort of superposition going on...