Sound

Sound is produced when vibrations are active in a medium. The vibrations create pressure in the air, which makes the air particles compress and expand. This can be explained by using a slinky: if you spread the slinky, and then take the one side and pull and push it. You will see that the slinky creates a strange wave. This is called a longitudinal wave, so sound travels in waves called longitudinal waves.

Sound requires a medium (air, water etc.) to travel through; therefore, it cannot travel in a vacuum. Sound travels at different speeds in different materials. In fact, it travels the slowest in air and fastest in solids. An echo is created when sound waves hit an object and reflects the sound.

The pitch of a sound is determined by the frequency. Frequency is the amount of waves that hits a specific spot every second. Hertz is the measurement used for measuring the frequency. A human’s hearing range is between 20 Hertz and 20,000 Hertz. So that means that we can hear a sound of 20 vibrations per second to 20,000 vibrations per second. The amplitude determines the volume of a sound.