Sound Flashcards
What is sound produced by?
by vibrating particles
What does sound need to travel through?
a medium; it can’t travel through a vacuum
What is a vacuum?
empty space with no air
What is a medium?
solid, liquid or gas
What is the speed of sound in:
air at sea level (average air)
water (liquid)
metal (gas)
330
1500
5000
What are echoes caused by?
reflection of sound.
What kind of waves are sound waves?
longitudinal waves
What are sound waves composed of?
compressions (where the air molecules are closer together) and rarefactions (where the air molecules are further apart).
Where do sound waves travel fastest and why?
in solids because the particles in a solid are closer together, causing the vibrations to be transmitted between them fast and thus, sound travels through faster compared to liquids and gases.
What are longitudinal waves?
waves created by in and out motion in the same direction the wave is travelling.
What are transverse waves created by?
up and down movement and move at right angles (90 degrees) to the direction of travel of the wave.
What is the outer ear made of?
it is made up of the pinna, auditory canal and eardrum.
What does the outer ear do?
it directs sound into your ear and the ear drum (membrane) vibrates when sound reaches it.
What is the middle ear made of?
it is composed of the ossicles (small bones). These are the hammer, anvil and stirrup. The eardrum passes the vibrations onto them.
What do the ossicles then do?
What is the unit of measurement for frequency?
hertz (Hz)
What affects the speed of sound in the air?
pressure, humidity and pressure
What is the difference between pitch and volume?
Pitch is the frequency of a sound, and volume is the loudness of a sound
What is the unit to measure the loudness of a sound?
decibel
What is the range of human hearing?
20Hz to 20kHz
What is the difference between sound absorption and sound reflection?
sound absorption is when sound waves are absorbed by a surface, and sound reflection is when sound waves bounce off a surface
What is an echo?
a reflection of sound waves
What is the equation to find speed?
speed (v) = distance (s) / time (t)
What is the equation to find distance?
distance (s) = speed (v) x time (t)
