Question

A wave has a wavelength of 4 × 10−7 m and a speed of 8 × 107 m/s in a particular material. What is its frequency in this material? Answer in units of Hz

Answer 1

According to the mathematical model, the wavelength has an inverse relationship with the frequency, the higher the frequency, the shorter the wavelength, and vice versa. The wavelength λ (lambda) is equal to the velocity v of the wave, divided by the frequency f:

`f = (c)/(\lambda)`

For our case we have that

`c = 8*10^7m/s`

`\lambda = 4*10^(-7)m`

Replacing to find the frequency we have that

`f = (8*10^7)/(4*10^(-7))`

`f = 2*10^(14) Hz`

Therefore the frequency in this material is
`f = 2*10^(14) Hz`