Radio waves travel in air at 3.0 x 108ms-1. If the waves enter water of refractive index \(\frac{4}{3}\), calculate the speed of radio waves in water

Radio waves travel in air at 3.0 x 10⁸ms^-1. If the waves enter water of refractive index \(\frac{4}{3}\), calculate the speed of radio waves in water

Answer Details

When radio waves travel from air to water, they change direction due to the change in speed caused by the change in medium. The speed of light in a vacuum is the fastest possible speed, denoted by "c" and equal to 3.0 x 10^8 m/s. The refractive index of a medium is the ratio of the speed of light in a vacuum to the speed of light in that medium, denoted by "n". The formula for calculating the speed of light in a medium is: v = c/n where v is the speed of light in the medium. In this case, the speed of light in air is 3.0 x 10^8 m/s and the refractive index of water is 4/3. So, v = (3.0 x 10^8 m/s) / (4/3) v = (3.0 x 10^8 m/s) x (3/4) v = 2.25 x 10^8 m/s Therefore, the speed of radio waves in water is 2.25 x 10^8 m/s, which is option (C).