Question #108b1

1 Answer
Dec 31, 2017

7 Hz

Explanation:

The number of beats per second is determined the difference of two frequencies. There are three possible differences coming from 3 three forks:

203-200 = 3 Hz
207-203 = 4 Hz
207-200 = 7 Hz

So in a one second, you can hear up to 7 beasts.
The difference between beats produced by two forks (200 & 207Hz) vs three forks (200, 203, 207) is that for the former each beat sounds just like the other while for the later they do not, i.e., some beats are louder than the others.