5th grade chapter 14 section 2 - what is sound energy

CHAPTER 14 SECTION 2

SOUND–a wave of vibrations that spreads from

its source.

• Vibration is the back-and-forth motion of an object.

Crest - areas where particles are very close together

Frequency - The number of crests that pass by a point each second

The greater the frequency is, the higher the pitch of the sound

Why Are Some Sounds Louder Than Others?

• The source of the louder sounds is vibrating more. • These sound waves have more

energy. • A sound’s loudness can be

measured in units called decibels.

YOUR VOICE

• Your vocal cords vibrate when you talk. • The vibrations are caused by air rushing past

them.• Your vocal cords make the particles in the air

around them vibrate. • These vibrations travel outward through the

air as sound waves.

How Does Sound Behave?• Sound can travel through solids,

liquids, and gases • It cannot travel through a vacuum,

which is empty space that contains no particles• The speed at which sound waves

travel is different in different materials.

Sound Transfers Energy• For a sound to be heard, energy must first cause

anobject to vibrate.

• Vibrating objects give off energy in sound waves in air.

• Some of the energy reaches your ear, and your eardrum absorbs some of the energy.

• In this way, the energy of the original material’s vibrations passes to you.

SOUND–a wave of vibrations that spreads from

its source.

• Vibration is the back-and-forth motion of an object.

Crest - areas where particles are very close together

Frequency - The number of crests that pass by a point each second

The greater the frequency is, the higher the pitch of the sound

Why Are Some Sounds Louder Than Others?

• The source of the louder sounds is vibrating more. • These sound waves have more

energy. • A sound’s loudness can be

measured in units called decibels.

YOUR VOICE

• Your vocal cords vibrate when you talk. • The vibrations are caused by air rushing past

them.• Your vocal cords make the particles in the air

around them vibrate. • These vibrations travel outward through the

air as sound waves.

How Does Sound Behave?• Sound can travel through solids,

liquids, and gases • It cannot travel through a vacuum,

which is empty space that contains no particles• The speed at which sound waves

travel is different in different materials.

Sound Transfers Energy• For a sound to be heard, energy must first cause

anobject to vibrate.

• Vibrating objects give off energy in sound waves in air.

• Some of the energy reaches your ear, and your eardrum absorbs some of the energy.

• In this way, the energy of the original material’s vibrations passes to you.