3 • Sound in strings and air columns

What happens when a string is disturbed?

Standing waves are set up in the string

Name 2 examples of Stringed Instruments

Violins

Guitars

What happens when the air inside a pipe is disturbed?

Standing waves are set up in the pipe

Name 2 examples of Wind Instruments

Harmonica

Tin Whistle

What happens when a tuning fork is held to the mouth of a pipe?

Standing waves are set up in the pipe

What effect do longer pipes have on notes?

The longer the pipe the lower frequency of the note

Label This Formula

Fundamental Frequency of Strings

f - fundamental frequency

l - length

T - tension

u - mass per unit length

What page of the log tables can you find the Fundamental Frequency formula?

59

Define This Frequency

Fundamental Frequency

l = lambda / 2

Define This Frequency

2nd Harmonics

l = lambda

Define This Frequency

3rd harmonic

l = 3 lambda / 2

Define these frequencies

Closed Pipes

a - funadmental frequency

b - 3rd harmonic

c - 5th harmonic

Define the length of the fundamental frequency in a closed pipe

lambda / 4

Define the length of the 3rd harmonic in an closed pipe

3lambda/4

Define the length of the 5th harmonic in an closed pipe

5 lambda/4

Name an example of a closed pipe instrument

Clarinet

Define these frequencies

Open Pipes

a - fundamental frequency

b - 2nd harmonic

c - 3rd harmonic

Define the length of the fundamental frequency in an open pipe

lambda / 2

Define the length of the 2nd harmonic in an open pipe

lambda

Define the length of the 3rd harmonic in an open pipe

3 lambda/2

Name an example of an open pipe instrument

Tin Whistle