Sound Flashcards
What type of wave is sound?
Longitudinal
What is an echo?
When a sound wave reflects off of an object
How do the properties amplitude, frequency and speed change when a wave is reflected?
Amplitude decreases
Speed and frequency stays the same.
How do the properties wavelength, frequency and speed change when a wave is refracted?
Wavelength and velocity decreases
Frequency stays the same
What are sound waves generated by?
Any object that vibrates.
How does sound energy travel?
Passed on by vibrating particles.
What is the name for the region of a longitudinal wave that is ‘bunched together’?
Compression
What is the name for the region of a longitudinal wave that is ‘spread out’?
Rarefaction
Can sound travel through a vacuum?
Why?
No.
There are no particles to pass on the sound energy.
What is ultrasound?
Sound above the human hearing range (20kHz)
What are some uses of ultrasound?
Dog whistle
Sonar
Ultrasound scans to check development of an unborn foetus.
Why is ultrasound used to scan unborn foetuses instead of X-rays?
Ultrasound is non-ionising, making it unlikely to hurt the mother or foetus.
How is speed calculated using an echo/sonar?
2D
Speed = ————-
Time
