Waves/ Ultrasound Flashcards
What is wavelength?
The length of a wave from one point of a wave to its consecutive point.
Wavelength (m) = wave speed (m/s) / frequency (Hz).
What is amplitude?
The displacement of a point on a wave from its equilibrium.
What is ultrasound?
A sound waves whose frequency is above 20kHz (human range), which is absorbed, reflected and transmitted by different materials off different densities.
What is frequency?
The amount of waves that pass through a point in a certain amount of time.
Frequency (Hz) = wave speed (m/s) / wavelength (m)
What are the two wave categories?
Mechanical (transverse/ longitudinal) and electromagnetic (transverse).
What’s a period?
The time it takes for one wave to pass through a point.
Time / number of cycles that has passed in that time
What is an echo?
The strongest reflection of a sound, where the sound wave’s speed is very different than the material is reflects off of.
Why wouldn’t normal sound produce images like an ultrasound does?
As they don’t go through many materials, rather reflect off of them.
What is the humans Hz range?
20Hz -20kHz
Why do we use ultrasound instead of X-rays?
Its not carcinogenic as it doesn’t cause mutations.
Describe longitudinal; waves:
Areas of compression next to areas of rarefaction, making particles move side to side.
What are the disadvantages of ultrasounds and X-rays.
Ultrasounds- poor resolution/ detail
X-rays- ionising radiation, can damage living cells,
What are the advantages of ultrasounds and X-rays.
Ultrasounds- Non-ionising, good for prenatal monitoring, produces images of soft tissues and fluids.
X-rays- Good 2D images resolution of bone structures.
How do you calculate wave speed?
frequency x wavelength
How do you calculate wavelength?
wave speed / frequency
