Answer:
λ = 437 m.
Explanation:
- Since a radio wave is a electromagnetic type of wave, it propagates approximately at the same speed of light in vacuum, 3*10⁸ m/s.
- As in any wave, there exist a fixed relationship between the propagation speed, the wavelength and the frequency of the radio wave, as follows:
[tex]c = \lambda* f (1)[/tex]
- Replacing by the values of the speed and the frequency, and solving for the wavelength λ, we get:
[tex]\lambda = \frac{c}{f} =\frac{3e8 m/s}{685.9e31/s} =437 m (2)[/tex]