Question

What is the wavelength (in air) of a 13.0 khz vlf radio wave?

Answer 1

Since,
Speed = Frequency * WaveLength

=> WaveLength = Speed / Frequency --- (A)

Frequency = 13.0 kHz.
As the radio waves are electromagnetic waves, their speed is equals to the speed of light. Therefore,
Speed = C = $3 * 10^{8} m/ s^{2}$

Plug in the values in equation(A):

A => WaveLength = $\frac{3 * 10^{8}}{13*10^{3}}$

Ans: Wavelength = 23.077 kilometers.
-i