00:02
Alright, so in this problem it says a horizontal wire is stretched with a tension of 94 newtons.
00:11
So let's go on first and write what we know.
00:15
We know that f is equal to 94 neutens, which is the tension in our wire.
00:20
It says the speed of transverse waves for the wire is 406 meters per second.
00:31
And it says, it asks, what must the amplitude of a traveling wave of frequency 6 ,9.
00:37
Hertz b for the average power carried by the wave to be 0 .365 watts.
00:43
So what must a be if the frequency is 69 hertz and the average power, call it p average, is equal to 0 .365 watts.
01:04
Well, there's a handy formula we can use for average power, which says this.
01:09
It says the average power carried by, a traveling wave is going to be one half times square root of mu times f times omega squared times a so first we'll note that this here is angular frequency and remember that angular frequency is 2 pi f so don't don't accidentally plug in f for omega here and what we can do is solve for the amplitude here.
01:57
Say, amplitude is a square root of two times the average power over root muf times omega squared.
02:11
And i'm going to simplify that to 1 over root, not over root 1 over 2 pi omega.
02:18
I'm sorry, 2 .5 f times the square root of 2 p average over root muf...