Sound Energy

Cian TaylorEmail: cian.taylor@ireland.com

Web: http://eduspaces.net/ciantaylor

Sound is a Form of Energy

• A table tennis ball hung in front of a speaker

• Ball will move as the sound waves hit it.

Sound wavesTable-tennis

ball

Conversion of Sound Energy

• Sound causes our eardrums to vibrate.

• This is an example of sound energy being converted from one form of energy to another, mechanical energy. Both forms are kinetic energy.

• Click on each box below to see how

- sound energy is converted to kinetic energy

- and to electrical energy

Conversion of Sound Energy

• Sound energy is converted into electrical energy in a telephone.

• How?– The sound energy is converted to electrical

energy by a microphone. Then into radiant energy when it is sent to the other phone.

Conversion of Sound Energy

• At the other end of the phone line

• The radiant energy is converted back to electrical energy which is converted back into sound energy.

Conversion of Sound Energy

Sound Transmission• Transmission means sending from one

place to another.

• Sound waves are transmitted by particles in the air.

Air MoleculesSpeaker

Ear

Animation courtesy of Dr. Dan Russell, Kettering University

Sound Transmission in Air

•Sound waves in air are passed between molecule

•What happens when you change frequency above?

Sound does not Travel in a Vacuum

sound.jar

http://phet.colorado.edu/index.php

Click on the graphic above to start the simulation.

• Sound travels at different speeds in different materials.

• In air..........................340 m/s

• In water.....................1500 m/s

• In steel.......................6000 m/s

The Speed of Sound

• Which is faster, the speed of light or the speed of sound?

• How do you know?

The Speed of Sound

• The speed of light is much faster!

• The speed of light........... 300,000,000 m/s

(approximately 186,282 miles per second )

• The speed of sound in air.... 340m/s

• (0.21 miles per second)

The Speed of Sound

Light and Sound• Fireworks:

- you see the firework explode before you hear the bang.

• Waves on a beach: - you’ll see the waves break before you hear them

breaking.

• Lighting: - you see the lightning before you hear the thunder.

http://en.wikipedia.org/wiki/File:Lightnings_sequence_2_animation.gif