This is an exercise to help you understand the Doppler Effect. You can control the above screen by pressing the buttons at the bottom. The red dot is the source of the sound. You can see the outwardly propagating compression waves coming from it. These move at the speed of sound. You can vary the velocity of the source and see the different effects it has on the sound waves. The speed is measured as the ratio of the source's speed to the speed of sound.
