1. Sound
SOL 5.2

2. Sound
Sound: the transfer of energy created by vibrating objects, sent through matter, from one place to another.
Sound needs matter to travel.
Sound can’t travel in a vacuum, or a place where there is very little or no matter.

3. Sound Sound travels as a compression wave.
A compression wave transfers energy by making molecules bump into each other (like the Newton’s Cradle).

4. Sound
Compression waves have areas where the molecules are more tightly packed. These are called areas of compression.
Compression waves have areas where the molecules are more loosely packed. These are called areas of rarefaction.

5. Compression Wave

6. Sound
Some materials cause sound to reflect or bounce off. This is called an echo.

7. Sound
Certain animals, like dolphins and bats, use echoes to navigate and locate food. This is called echolocation.

8. Wavelength
Wavelength: The distance between a point on one wave to the same point on the next wave.
In a compression wave, it is usually measured from the middle or one area of compression or rarefaction to the middle of the next.

9. Wavelength

10. Frequency & Pitch
Frequency: The number of waves in a given unit of time. Measured in Hertz (Hz).
Pitch: the highness or lowness of a sound.
The faster a wave moves, the higher its frequency. The higher the frequency, the higher the pitch.

11. Frequency & Pitch ____________________ ____________________
Which picture shows a high frequency/pitch and which shows a low frequency/pitch?
____________________

12. Volume
Volume: The loudness or softness of a sound. Measured in Decibels (dB). Higher dB = louder sound
Volume is different than pitch. Volume is affected by the amount of energy causing something to vibrate.

13. Volume