When we swing a stick in air (one way.. not back and forth), we hear sound if we swing it fast enough. Is the reason we hear it because by swinging fast enough we also make the amplitude of sound wave larger or we change the frequency of sound by doing that? (or both)
I know that the source determines the frequency of any kinds of waves. What exactly determines the frequency of sound in this example and how?
I'm a bit confused because we are not swinging it back and forth.