Flashcards

Sound

Aarushi Jain Physics IGCSE English 7 cards

Cards in this deck (7)

1What are sounds?Produced by objects that are vibrating.
Air molecules pushed closer together, creating compression and push against neighbouring molecules. Behind compression is spread out region of particles called rarefaction. Series of rarefactions and compressions is longitudinal sound wave.
2Sound waves in different materialsCan travel in solids, liquids, gases.
Can't travel through vacuum because no particles to carry vibrations.
Speed of sound approx. 340 m/s in air.
3ReflectionWhen sound wave strikes surface, may be reflected. Like light waves, reflected from surface so angle of incidence = angle of reflection.
Reflected sound wave is echo.
Echo sounding - sound waves emitted from ship to seabed, equipment on ship detects sound waves reflected back - calculates depth of sea by calculating time between sending sound wave and receiving echo.
4DiffractionWavelength of some sound waves approx. equal to width of doorway so waves will spread out as pass through door.
5Pitch and FrequencySmall objects like strings of violin vibrate quickly and produce sound waves with high frequency. Sounds heard as notes with high pitch.
Others, like strings of cello, vibrate more slowly so lower frequency and pitch.
Therefore, high frequency = high pitch, low frequency = low pitch
6Audible RangeAudible hearing range - 20 - 20000 Hz.
Ultrasounds: > 20000 Hz E.G. dolphins
Infrasound's: > 20 Hz E.G. elephants
7LoudnessLarge amplitude - louder sound
Small amplitude - quieter sound

Description: IGCSE Physics Flashcards on Sound, created by Aarushi Jain on 10/11/2016.
Created by: Aarushi Jain
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