00:01
We are told that the frequency of an a note is supposed to be 440 hertz, and the frequency of an e note is supposed to be 659 hertz.
00:20
For part a, the third harmonic of the a note is just three times 440 hertz.
00:29
The second harmonic of the e node is just 2 times 659 hertz.
00:47
I'm going to put that in a calculator.
00:57
3 times 440 minus 2 times 659 gives me 2 hertz.
01:15
Okay, 2 hertz.
01:19
B.
01:33
The answer to b is going to be the same as a, 2 beats per second.
01:44
Because f subbeat is just f mod, 2f mod, i mean, which is f2 minus f1.
01:59
So that would be the same.
02:05
But what if there were four beats per second? that's what is asking us in part c.
02:13
So now f beat equals four beats...