Sound, light and electromagnetic waves are all types of waves
All waves can be reflected and refracted
Doppler Effect:
When a car is not moving and its horn sounds, the sound waves we receive are a series of evenly spaced wavefronts.
If a car is moving, wavefronts of the sound are no longer evenly spaced.
Ahead of the car wavefronts are compressed as the car is moving in the same direction as the wavefronts. This creates a shorter wavelength and a higher frequency.
Behind the car wavefronts are more spread out as the car is moving away from the previous wavefronts. This creates a longer wavelength and a lower frequency.
