Question

To navigate, a porpoise emits a sound wave that has a wavelength of 4.9 cm. The speed at which the wave travels in seawater is 1522 m/s. Find the period of the wave.

Answer 1

Frequency can be defined as the ratio between the speed of the wave and its wavelength, that is

$f= \frac{v}{\lambda}$

At the same time, the frequency is the inverse of the Period so

$T = \frac{1}{f}$

If we join the two expressions we will have to

$T = \frac{\lambda}{v}$

Replacing we have that

$T = \frac{4.9*10^{-2}}{1522}$

$T = 3.219*10^{-5} s$

Therefore the period of the wave is $3.219*10^{-5} s$