Number of wavelengths, N = d/λ
d = vt/2 = (324)(4.5)/2 = 729 m
A student standing in a canyon yells "echo", and her voice produces a sound wave of the frequency of f= 0.55 kHz. The echo takes t = 4.5 s to return to the student. Assume the speed of sound through the atmosphere at this location is v=324 m/s.
f = 0.55 kHz
t = 4.5 s
v = 324 m/s
How many wavelengths are between the student and the wall?