This question is not complete, the complete question is;
Amateur radio operators in the United States can transmit on several bands. One of those bands consists of radio waves with a wavelength near 20 m . Calculate the frequency of these radio waves.
Answer: frequency of the radio waves is 15 MHz
Step-by-step explanation:
Given that;
wavelength λ = 20 m
we know that; Speed of light C = 3 × 10⁸ m/s
frequency f = ?
we know that;
frequency f = Speed of light C / wavelength λ
so we substitute
frequency f = (3 × 10⁸m/s) / (20m)
frequency f = 15 × 10⁶ Hz
we also know that 1 Hertz = 0.000001 Megahertz
so
frequency f = 15 × 10⁶ Hz × 0.000001
frequency f = 15 MHz
Therefore frequency of the radio waves is 15 MHz