Sound Flashcards
What are waves?
Waves are vibrations which transfer energy as they move. Both sound, and light travels in waves. There are two different types - transverse, and longitudinal.
How can we measure waves?
We measure waves by the amplitude, wavelength, and the frequency.
What is the amplitude?
The height of crest (top) or trough (bottom) of a wave when measured from the rest position.
What is the crest?
The top of a wave.
What is the trough?
The bottom of a wave.
What is the wavelength?
The maximum distance between two crests, or troughs.
What are transverse waves?
Like the ripples on a water surface. Matter travels up and down at 90 degrees to the direction the wave is travelling. Light waves are another example of a transverse wave. (e.g rope up & down = transverse)
What is frequency?
The number of waves that pass a point in one second. Measured in Hertz (Hz).
What is sound?
Sound can be described by using the terms ‘pitch’, and ‘loudness’. Soundwaves can be visualised by using a piece of equipment called an ‘oscilloscope’. It produces graphs.
Define Pitch:
A term used to describe the frequency of a sound wave. A larger frequency is equal to a higher pitch.
Define Loudness:
Loudness is related to amplitude. A larger amplitude means a louder sound.
What are echos?
When sound is reflected off an object, and it goes back to the listener.
What are longitudinal waves?
The matter carrying a longitudinal wave vibrates parallel to the direction the wave is travelling by alternating between compression and stretching. Sound waves are longitudinal waves. (e.g slinky push = longitudinal)
Low pitch = ?
Less waves per second.
How can we hear echos?
We have to hear the sound for 0.01 seconds. If the sound waves reach our ear before this time is up, we hear the echo. The other condition, is there has to be a minimum distance between object and person of 17.2m. There should also be very few sound absorbing materials present.
