sound

• Sound waves are longitudinal waves. They can be reflected and diffracted in the same way as transverse waves.

• Sounds are produced by objects that are vibrating. When the waves enter the ear, they strike the ear drum and make it vibrate in the shape of the waves. These vibrations are then changed to electrical signals which the brain picks up.

• Sound waves can travel through:-

Solids- this is why you can hear things on the other side of the door, even when it is closed.

Liquids-this is why whales can communicate with each other when they are under water.

 Gases- the sound waves we create when we speak travel through the gases in the air.

Sound waves cannot travel through a vacuum because there are no particles to carry the vibrations.

• You can measure the speed of sound by:

Measuring the speed using echoes

Using a resonance tube and a tuning fork

Measuring the speed of sound using an oscilloscope.

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