Final answer:
When three adjacent piano keys (F, F-sharp, G) are struck simultaneously, producing frequencies of 349, 370, and 392 Hz respectively, they produce beat frequencies of 21 Hz between F and F-sharp and 22 Hz between F-sharp and G.
This correct answer is none of the above.
Step-by-step explanation:
The question concerns the beat frequencies produced when three adjacent keys on a piano are struck simultaneously.
These keys have specific frequencies associated with each of them: F (349 Hz), F-sharp (370 Hz), and G (392 Hz). The beat frequency is the difference in Hz between two frequencies.
When two notes are played together, if their frequencies are close to each other, they produce a pulsation effect as they go in and out of phase with each other, known as a beat.
To find the beat frequency between F (349 Hz) and F-sharp (370 Hz), subtract the smaller frequency from the larger: 370 Hz - 349 Hz = 21 Hz.
To find the beat frequency between F-sharp (370 Hz) and G (392 Hz), again subtract the smaller frequency from the larger: 392 Hz - 370 Hz = 22 Hz.
Therefore, the discordant combination of the three notes will produce beat frequencies of 21 Hz and 22 Hz.
This correct answer is none of the above.