What is the Frequency of the Sound Wave Produced by a Vibrating Guitar String?

Click For Summary
SUMMARY

The discussion focuses on the frequency of sound waves produced by a vibrating guitar string, specifically a 63.5-cm string tuned to B3 with a fundamental frequency of 245 Hz. The speed of transverse waves on the string is calculated to be 311.15 m/s, and upon increasing the tension by 1.0%, the new fundamental frequency is determined to be 246.2 Hz. The participant struggles with calculating the frequency of the sound wave in air and seeks guidance on this aspect, while also needing to find the wavelength of the sound wave produced.

PREREQUISITES
  • Understanding of wave mechanics and sound propagation
  • Familiarity with the equations for wave speed and frequency
  • Knowledge of tension and linear mass density in strings
  • Basic principles of sound waves in air
NEXT STEPS
  • Learn how to apply the wave equation to calculate sound frequency in different media
  • Study the relationship between frequency, wavelength, and wave speed
  • Explore the effects of tension on string vibration and frequency
  • Investigate the concept of harmonics in stringed instruments
USEFUL FOR

Students studying physics, particularly those focused on wave mechanics, musicians interested in the physics of sound, and educators teaching concepts related to sound waves and string instruments.

Northbysouth
Messages
241
Reaction score
2

Homework Statement


One of the 63.5-cm-long strings of an ordinary guitar is tuned to produce the note B3 (frequency 245 Hz) when vibrating in its fundamental mode.

A) Find the speed of transverse waves on this string.

B) If the tension in this string is increased by 1.0%, what will be the new fundamental frequency of the string?

C) If the speed of sound in the surrounding air is 344 m/s, find the frequency of the sound wave produced in the air by the vibration of the B3 string.

D) If the speed of sound in the surrounding air is 344 {\rm m/s}, find the wavelength of the sound wave produced in the air by the vibration of the B3 string.

Homework Equations


v = sqrt(T/μ) where T is tension and μ is the linear mass density which is equal to mass/length

fn = n*v/(2L) where n is the mode, v is the wave speed and l is the length


The Attempt at a Solution



I was able to solve parts A and B like so:

A) 2L*fn/n = v

thus

v = 2*0.635 m * 245Hz/1
v = 311.15 m/s

B)

I multiplied v by sqrt(1.01) thus v*sqrt(1.01) = 312.702

so

fn = (1*312.702 m/s)/(2*0.635m)
fn = 246.2 Hz

C) This is the part I'm stuck with. I tried:

fn = (1*344 m/s) / 2*0.635m)
fn = 270.9 Hz

My answer is wrong and I can't figure out how else to approach this problem. Could someone point me in the right direction?

D) I haven't tried to solve this part yet as I figured I probably need part C, or at the very least part C would help me solve it.
 
Physics news on Phys.org
Got it. Thanks.
 

Similar threads

  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
3
Views
2K
  • · Replies 19 ·
Replies
19
Views
5K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
Replies
20
Views
5K