Answer
$3.8$ m
Work Step by Step
To find the wavelength of a sound using the frequency and velocity of the wave, use the formula relating these values, which is $$v=f \lambda$$ Solving for $\lambda$ (wavelength) yields $$\lambda = \frac{v}{f}$$ Using the standard speed of sound measurement of $343m/s$, the wavelength equals $$\lambda = \frac{343m/s}{90Hz}=3.8m$$
