Question

An ultrasound pulse has a wavelength of 1.0mm. Its speed in water is 1400m. What’s the frequency?

Answer 1

`1.4\cdot 10^6 Hz`

Step-by-step explanation:

The relationship between the frequency, the wavelength and the speed of a wave is given by the wave's equation:

`v=f \lambda`

where

v is the speed of the wave

f is the frequency

`\lambda` is the wavelength

For the pulse in this problem,

`\lambda = 1.0 mm = 0.001 m\\v = 1400 m/s`

Solving for f, we find the frequency:

`f=(v)/(\lambda)=(1400)/(0.001)=1.4\cdot 10^6 Hz`