Sound Flashcards
Sound needs a medium
Put an alarm clock or buzzer inside a bell jar and connect it to a vacuum pump.
As air is removed , the sound becomes fainter .
Conclusion = sound needs a medium in which to travel.
Sound
Is a form of energy
Produced by vibrations
Sound can travel through a solid liquid or gas
It can not travel through a vacuum
Speed of sound and air
The sped of sound in air is 340m/s , light is 3✖️10 to the power of 8 . This is why we see lightening befor we hear thunder
Echoes and ultrasounds
An echo is a reflection of sound
Ultrasound is sound above are level of hearing
Echoes & ultrasound have a lot of uses
Pregnant mothers can get a picture of their baby
Bats can find their way
Ear protection
If people are working in a job where sound is above 70db they have to wear ear protection
Permanent ear damage
Sound over 115db can cause permanent damage
Energy conversions in hearing
The movement kinectic energy is converted to electrical energy and goes to the brain to be processed
Loud sounds
The loudness of a sound is called the sound intensity level .
Sound intensity is measured in decibels .
A sound level meter is used to measure the loudness of sound in decibels .