Sound Energy and Its Properties

1. Properties
of Sound
Science 5
March 10, 2021

2. Sound
Produced by vibrations (back-and-forth movement)
A form of energy; carried by waves

4. Speed of sound = about 1230 km/h or about 340 m/s
Sound wave - a pattern produced by air particles being pushed
together, causing the surrounding air to vibrate

5. Sound waves are received by the ears and interpreted by the brain.

6. Sound waves cannot move through a vacuum because there is no
medium present to vibrate.
Sound needs something to move through.

7. Sound waves travel faster in water
than in air.
Sound waves travel fastest in
solids.

8. When a sound wave strikes a smooth, hard surface, it bounces back.
ECHO

9. When sound energy strikes a rough or soft material, it passes through
the material (absorbed) and is reduced.

10. Properties
of
Sound

11. Pitch The degree of lowness or highness of
sound
When vibrations are
fast, high notes are
heard.
When vibrations are slow,
low notes are heard.

12. High-frequency = high pitch
The number of vibrations within a period of time
Measured in Hertz (Hz)
1 Hertz = 1 vibration/second
Low-frequency = low pitch
Frequency

13. String instruments
Length of String
Shorter strings = high pitch
Longer strings = lower pitch
Thickness of String
Thinner strings = high pitch
Thicker strings = low pitch
Tension
Stretched/high-tension string = high pitch
Loose/low-tension strings = low pitch

14. Quality The shape of the sound waves
produced by an object
The smoother the shape of the
waves, the better is the quality
of the sound and the more
pleasing it is to the ears.
Ragged-shaped waves produce
noise (unpleasant sound).

15. The volume or sound pressure produced by the
vibrations of an object
Measured in decibels (dB)
Loudness
High-pressure sounds
produce loud sounds.