How does sound travel through a medium

Unfortunately children will not always accept that the light and sound are from the same instantaneous release of energy. It is, however, possible to watch a sound being made at some distance away and to detect a slight delay in hearing the sound.

Exploding fireworks, the click of a ball on a cricket bat and a child bashing a dustbin lid at the other end of a playing field will all provide this opportunity.

Sound travels in solids and liquids too. Sound waves travel faster and more effectively in liquids than in air and travel even more effectively in solids.

This concept is particularly hard to believe since our general experiences lead us to hear reduced or garbled sounds in water or behind a solid door.

There are reasons for this. Most of our everyday experiences are when a sound travels first through air and then through water or a solid. Light travels much faster than sound through air. For example, a person fires a starting pistol and raises their hand in the air at the same time. A distant observer stood metres m away records the time between seeing the action the light reaches the time keeper immediately and hearing the sound which takes more time to cover the same distance.

The speed of sound can be calculated using the equation:. This is when:. An observer m away records a 1. A mechanical wave is a disturbance that moves and transports energy from one place to another through a medium.

In sound, the disturbance is a vibrating object. And the medium can be any series of interconnected and interactive particles. This means that sound can travel through gases, liquids and solids. Let's take a look at an example. Imagine a church bell. When a bell rings, it vibrates, which means the bell itself flexes inward and outward very rapidly.

As the bell moves outward, it pushes against particles of air. Those air particles then push against other adjacent air particles, and so on. As the bell flexes inward, it pulls against the adjacent air particles, and they, in turn, pull against other air particles. This push and pull pattern is a sound wave. The vibrating bell is the original disturbance, and the air particles are the medium.

Sound isn't restricted to moving through the air. Press your ear against a solid surface like a table and close your eyes. Tell someone else to tap his or her finger on the other end of the table.