Skip to main content
Ch 17: Superposition
Chapter 17, Problem 17

A flute player hears four beats per second when she compares her note to a 523 Hz tuning fork (the note C). She can match the frequency of the tuning fork by pulling out the 'tuning joint' to lengthen her flute slightly. What was her initial frequency?

Verified Solution

Video duration:
3m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Beats Frequency

Beats frequency occurs when two sound waves of slightly different frequencies interfere with each other, resulting in a periodic variation in amplitude. The frequency of the beats is equal to the absolute difference between the two frequencies. In this case, the flute player hears four beats per second, indicating that the frequency of her note differs from the tuning fork's frequency by 4 Hz.
Recommended video:

Frequency Matching

Frequency matching is the process of adjusting the frequency of a sound source to match a reference frequency. In this scenario, the flute player adjusts her flute's length to match the 523 Hz frequency of the tuning fork. The initial frequency of her note can be determined by adding or subtracting the beats frequency from the reference frequency.
Recommended video:
Guided course
05:08
Circumference, Period, and Frequency in UCM

Tuning Fork

A tuning fork is a metal instrument that produces a specific pitch when struck, commonly used for tuning musical instruments. The frequency of the tuning fork provides a standard reference point for musicians. In this question, the 523 Hz tuning fork represents the note C, which the flute player aims to match by adjusting her instrument.
Recommended video:
Guided course
06:22
Weird Arrangement (Re-Drawing Resistors)