To find the frequency of the unknown tuning fork, we can use the information about the beats produced when it vibrates with two known frequencies: 256 Hz and 253 Hz.
Understanding Beats
Beats occur when two sound waves of slightly different frequencies interfere with each other. The beat frequency is the absolute difference between the two frequencies.
Calculating the Unknown Frequency
Let the frequency of the unknown tuning fork be represented as f.
- When f is paired with 256 Hz, the beat frequency is 6 beats/s:
- When f is paired with 253 Hz, the beat frequency is 3 beats/s:
Setting Up Equations
From the first condition:
- f - 256 = 6 → f = 262
- 256 - f = 6 → f = 250
From the second condition:
- f - 253 = 3 → f = 256
- 253 - f = 3 → f = 250
Finding the Valid Frequency
The possible frequencies from the equations are 262 Hz, 250 Hz, and 256 Hz. However, only 250 Hz satisfies both conditions:
- For 256 Hz: |250 - 256| = 6
- For 253 Hz: |250 - 253| = 3
Final Answer
The frequency of the unknown tuning fork is 250 Hz.