Answer:
F = 268 Hz
Explanation:
The beat frequency is given as:
[tex]Beat Frequency = |Frequency 1 - Frequency 2|\\[/tex]|
So, for the first flute and tuning fork:
[tex]20 Hz = |248 Hz - F|[/tex]
where,
F = Frequency of tuning fork
F = 248 Hz ± 20 Hz
F = 268 Hz (OR) 228 Hz
Now, for the second flute and tuning fork:
[tex]20 Hz = |288 Hz - F|[/tex]
where,
F = Frequency of tuning fork
F = 288 Hz ± 20 Hz
F = 268 Hz (OR) 308 Hz
Since, 268 Hz is common from both calculations. Therefore, it will be the frequency of the tuning fork.
F = 268 Hz