unit 1 quiz Flashcards
Sound is…
A mechanical and longitudinal wave
Power is…
Measured in milliwatts, proportional to amplitude squared, and intensity is proportional to power
The wavelength for a 5 MHz sound wave in tissue is about
0.3 mm
Wavelength = 1.54 /F(MHz)
Wavelength = 1.54 / 5
Wavelength = 0.3 mm
Acoustic parameters
Period, propagation speed and frequency
Sound can propagate through…
Titanium, water and piezoelectric materials
Sound cannot propagate through…
A vacuum
Speed of sound materials listed from lowest to highest
Air, water, tissue and bone
Only determined by sound source
Frequency, period, amplitude, power and intensity
Determined by a medium
Speed
Determined by sound and a medium
Wavelength
Average speed of sound
1540 m/s
The inertia of the medium describes its…
Density
Wavelength is related to…
Inversely related to frequency and directly related to period
The distance over which one cycle occurs
Wavelength
Density and propagation speed are
Inversely related
Measurement for propagation speed
Millimeters per microsecond
Peak to peak is…
Wavelength
If the transmit voltage is increased from 2 to 4 Volts, the frequency will…
Not change
0 - 20 Hz
Infrasound
2 MHz - 20 MHz
Diagnostic Ultrasound
20 Hz - 20 kHz
Audible sound
> 20 kHz
Ultrasound
What happens to the intensity if the amplitude is increased by a factor of 3?`
Increases by a factor of 9, bc amplitude squared
What happens to intensity if the power is increased by a factor of 3
Increases by a factor of 3, bc intensity and power are =
What are the 3 direct sound parameters
Amplitude, power and intensity
What are the 3 acoustic VARIABLES
Pressure, density and distance
What are the 3 BIGNESS parameters
Amplitude, power and intensity
