# Shared Flashcard Set

## Details

Cumulative Test I
n/a
50
Physics
09/17/2008

Term
 Tera
Definition
 10^12
Term
 giga
Definition
 10^9
Term
 mega
Definition
 10^6
Term
 kilo
Definition
 10^3
Term
 hecto
Definition
 10^2
Term
 deca
Definition
 10^1
Term
 pico
Definition
 10^-12
Term
 nano
Definition
 10^-9
Term
 micro
Definition
 10^-6
Term
 milli
Definition
 10^-3
Term
 centi
Definition
 10^-2
Term
 deci
Definition
 10^-1
Term
 define compressions
Definition
 areas where sound is dense
Term
 define rarefactions
Definition
 areas where sound is less dense
Term
 what is the number of Hz of infrasound
Definition
 <20Hz
Term
 what is the number of Hz for audible sound
Definition
 10Hz-20,000 Hz
Term
 what is the number of Hz for ultrasound
Definition
 20,000Hz-1,000,000Hz
Term
 what are the Hz of diagnostic medical ultrasound
Definition
 1,000,000Hz-30,000,000Hz
Term
 what is the average speed of sound in soft tissue
Definition
 1540 m/s
Term
 what is the equation to find decibels
Definition
 dB=10log(I/I0)
Term
 What is the unit of mass/weight
Definition
 kg
Term
 what is the unit of length
Definition
 m
Term
 what is the unit of area
Definition
 m^2
Term
 what is the unit for volume
Definition
 m^3
Term
 what unit is energy measured in
Definition
 joules
Term
 what is power and what unit is it measured in?
Definition
 rate of energy transport, joules/second
Term
 How is intensity measured
Definition
 Watt/Cm^2
Term
 What is the formula to find decibels?
Definition
 dB=10log(I/I0)
Term
 since ultrasound has no reference intensity, what replaces the reference intensity
Definition
 transmitted
Term
 Every time the intensity _____ the decibels go up by _____.
Definition
 doubles, 3
Term
 What is the velocity of a wave in soft tissues?
Definition
 1540 m/s
Term
 What is the relationship of velocity to frequency and wavelength?
Definition
 velocity is equal to the frequency multiplied by the wavelength
Term
 What is the relationship of frequency to period?
Definition
 frequency is equal to 1/period and vice versa
Term
 In what unit is Hertz measured and what is it a measure of?
Definition
 the per second and frequency
Term
 What units are used to measure period?
Definition
 seconds
Term
 define period
Definition
 the time it takes to complete one cycle
Term
 define frequency
Definition
 the number of oscillations per second
Term
 define wavelength
Definition
 the distance traveled in one cycle
Term
 define bulk modulus
Definition
 the measure of compressibility
Term
 What is a transducer
Definition
 converts one form of energy into another with a known fixed relationship between input and output energies
Term
 what is the piazoelectric effect
Definition
 when a mechanical force is applied to the face of the crystal and an electrical signal is generated
Term
 what is curie point
Definition
 the temperature above which the crystal loses its piazoelectric capabilities
Term
 What is true when the most efficient operation of the transducer crystal is achieved?
Definition
 the thickness of the crystal is 1/2 the wavelength
Term
 what dampens the crystal vibrations and minimizes reflected sound waves from air between itself and the crystal
Definition
 backing
Term
 what is acoustic impedence
Definition
 when there is an interface of two tissues where the acoustic impedence differs. a fraction of the wave will be reflected
Term
 How is the acoustic impedence measured (Z)
Definition
 rayls
Term
 what is a rayl
Definition
 kg/m^2/second
Term
 what is the equation to find the amplitude reflection coefficient: (R)
Definition
 R=(z2-z1)/(z2+z1)
Term
 Z=
Definition
 pv
Term
 what is sound
Definition
 a mechanical energy or disturbance that moves a pressure wave through a medium
Supporting users have an ad free experience!