Waves Flashcards
What are sound waves known as?
Longitudinal waves
The denser the medium, the
faster the sound travels through it
What frequency of sound can human hear?
20-20 000Hz
The greater the amplitude the…
more energy and so the louder it is.
The higher the frequency the higher the…
pitch.
Frequency=
The number of complete vibrations per second
kHz is
1000Hz
MHz is
100000Hz
What sort wavelength does a high frequency sound produce?
a shorter wavelength
Sawtooth waveform
sloping ups and vertical downs or vice versa reates a buzzy brassy sound
Pulse wave
Rectangular peaks and troughs, makes a thin reedy sound.
square wave
Peaks the same length as trough, makes a hollow sound.
triangle wave
similar to sine waves but make a weaker more mellow sound.
What is ultrasound?
Sound with a higher frequency than we can hear.
What is meant by partial reflection?
When a wave passes from one medium to another some of the wave is reflected off the boundary and some is transmitted.
What is used to find the distance to the boundary?
The time taken and speed taken for the ultrasound to be reflected back.
Advantages of ultrasound cleaning.
Can clean delicate mechanisms, be directed into precise areas and are extremely effective at removing dirt and other deposits.
How does ultrasound remove dirt?
Breaks up dirt and crud into very small particles which just fall off the equipment.
What can ultrasound be used for?
Industrial cleaning, industrial quality control (echos processed by a computer) and pre- Natal scanning.
