Guitar String and frequencies?

In summary, you calculated the velocity of a guitar string using the given length, mass, and tension, and then used that value to find the frequencies of the fundamental and first two overtones by setting the wavelength equal to 2 times the bridge-to-support-post length divided by the harmonic number. Your final answers were 320.7 Hz for the fundamental, 641.3 Hz for the second harmonic, and 962.0 Hz for the third harmonic.
  • #1
gmmstr827
86
1

Homework Statement



A guitar string is 90.0 cm long and has a mass of 3.16 g. From the bridge to the support post is 60.0 cm and the string is under a tension of 520 N. What are the frequencies of the fundamental and first two overtones?

L_s = 90.0 cm = .9 m
L_bsp = 60.0 cm = .6 m
m = 3.16 g = .00316 kg
F_t = 520 N

Homework Equations



v = sqrt(F_t*L_s/m)
v = λf >>> λ = v/f
λ = 2L_bsp/n; n = 1 for fundamental, n = 2 for 2nd harmony, etc.

The Attempt at a Solution



Find the velocity:
v = sqrt(TL_s/m)
v = sqrt[(520 N)(0.900 m)/(3.16e-3 kg)]
v = 384.8 m/s

Fundamental:
Set λ = v/f and λ = 2(L_bsp)/n equal to each other, n = 1, plug in other variables, solve for f.
(384.8 m/s)/f = 2(0.600 m)/1
384.8 m/s = (1.200 m)f
f = 320.7 Hz for the fundamental

Second harmonic:
Repeat same steps as the fundamental, but with n = 2.
(384.8 m/s)/f = 2(0.600 m)/2
384.8 m/s = (0.600 m)f
f = 641.3 Hz for the second harmonic.

Third harmonic:
Repeat the same steps as the fundamental and second harmonic, but with n = 3.
(384.8 m/s)/f = 2(0.600 m)/3
384.8 m/s = (2(0.600 m)/3)f
f = 962.0 Hz for the third harmonic.^^^ Does this all look correct?
 
Last edited:
Physics news on Phys.org
  • #2


Yes, your calculations and methodology are correct. Your final answers for the fundamental and first two overtones are also correct. Great job!
 

1. What are guitar strings made of and how does it affect the frequencies produced?

Guitar strings are typically made of steel, nickel, or bronze. The material used can affect the tension and density of the string, which in turn impacts the frequency produced when the string is plucked. Thicker strings tend to produce lower frequencies, while thinner strings produce higher frequencies.

2. How does the length of a guitar string impact the frequency it produces?

The length of a guitar string is directly related to the frequency it produces. A shorter string will vibrate at a higher frequency, while a longer string will vibrate at a lower frequency. This is why fretting a string at different points on the guitar neck can produce different pitches.

3. Can different types of guitar strings produce different frequencies?

Yes, different types of guitar strings can produce different frequencies. As mentioned before, the material and thickness of the string can affect the frequency produced. Additionally, the winding of the string (roundwound, flatwound, etc.) can also impact the frequency and tone produced.

4. How does tuning a guitar affect the frequencies of the strings?

Tuning a guitar refers to adjusting the tension of the strings to produce specific frequencies or notes. Each string is typically tuned to a specific frequency, with the lower strings producing lower frequencies and the higher strings producing higher frequencies. When all strings are in tune, they work together to produce a harmonious sound.

5. How do harmonics and overtones play a role in the frequencies produced by guitar strings?

Harmonics and overtones are additional frequencies that are produced when a string is plucked or strummed. These frequencies are multiples of the fundamental frequency (the main frequency produced by the string). They can add depth and complexity to the sound of the guitar and are often used in playing techniques such as harmonics and bending.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
819
  • Introductory Physics Homework Help
Replies
2
Views
1K
Replies
3
Views
944
  • Introductory Physics Homework Help
Replies
4
Views
822
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
205
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
3K
Back
Top