Question

What is the frequency of a pressure wave of wavelength 2.5 m that is traveling at 1400 m/s?

Answer 1

The relationship between the speed, the frequency and the wavelength of a wave is given by:
$f= \frac{v}{\lambda}$
where
f is the frequency
v is the speed of the wave
$\lambda$ is its wavelength

for the pressure wave in this problem, $\lambda=2.5 m$ and v=1400 m/s, therefore its frequency is
$f= \frac{v}{\lambda}= \frac{1400 m/s}{2.5 m}=560 Hz$