Frequency of standing waves in an open-closed pipe:

f_{n} = nv/4L

Speed, wavelength & frequency related by

v = λf

Assume v = 343 m/s in air

Remember n is counted as half-wavelengths

Draw a picture of standing waves with n=3 and n=5 in a pipe with one open end. Consider the following variables: frequency f, wavelength (lamda λ), sound of speed (v), mode number n, and pipe length (L). If you used the same tuning fork to create the two standing waves, which of these variables have changed between the two standing waves and which have remained the same? Explain.