a transverse wave has particles that move in a - ✔️✔️perpendicular direction (right
angles or 90 degrees) to the wave direction
acoustic variables identify which waves are sound waves, when an acoustic variable
changes in time a - ✔️✔️sound wave is present
length is measured in - ✔️✔️cm, feet
area is measured in - ✔️✔️cm^2, feet^2
volume is measured in - ✔️✔️cm^3, feet^3
percent is not - ✔️✔️a unit
increase by a factor means - ✔️✔️to multiply
decrease by a factor means - ✔️✔️to divide
how many hertz is 3 MHZ - ✔️✔️3,000,000
how much bigger is a billion than a million - ✔️✔️1000 times
how many milliliters are contained in a jar filled with 5 liters of fluid - ✔️✔️5000
how many liters are in 80 ml of fluid - ✔️✔️0.080
macro means - ✔️✔️bigger
micro means - ✔️✔️smaller
the effects of the medium upon the sound wave - ✔️✔️acoustic propagation properties
the effects of the sound wave upon the biologic tissue - ✔️✔️biologic effects
a type of wave that carries energy not matter from place to place - ✔️✔️sound
areas of increased pressure and density - ✔️✔️compressions
areas of decreased pressure and density - ✔️✔️rarefractions
,sound must travel through a medium, sound cannot travel through a - ✔️✔️vacuum
sound is a - ✔️✔️mechanical, longitudinal wave
sound travels in a - ✔️✔️straight line
three acoustic variables are - ✔️✔️pressure, density, and distance
pressure is - ✔️✔️a concentration of force within an area
pressure is found by - ✔️✔️force/area
unit of pressure is - ✔️✔️pascals (Pa)
density is - ✔️✔️concentration of mass within a volume
unit of density is - ✔️✔️kg/cm^3
distance is - ✔️✔️measure of particle motion
unit of distance - ✔️✔️mm or cm
unit of density - ✔️✔️kg/cm^3
a longitudinal wave has particles move back and forth in the - ✔️✔️same direction as
the wave
acoustic variables - ✔️✔️identify which waves are sound waves
acoustic parameters - ✔️✔️describe the features of a particular sound wave
period is measured in - ✔️✔️units of time (microsec)
the time required to complete a single cycle
example would be -high school class is 50 minutes - ✔️✔️period
period is determined by the - ✔️✔️sound source
Can period be changed by the sonographer? - ✔️✔️No, cannot be changed by
sonographer
, frequency is - ✔️✔️the number of certain events that occur in a particular time duration
units of frequency - ✔️✔️per second, 1/second, hertz, Hz
hertz is another way of saying - ✔️✔️per second
Frequency is determined by the - ✔️✔️sound source
Can frequency be changed by the sonographer? - ✔️✔️No, cannot be changed by
sonographer
typical frequency values include - ✔️✔️2 MHz to 15 MHz
humans can hear frequency's - ✔️✔️between 20 Hz and 20,000 Hz
ultrasound can hear frequency's - ✔️✔️greater than 20,000 Hz (too high for humans to
hear)
infrasound is - ✔️✔️less than 20 Hz (below human and ultrasound)
period and frequency are - ✔️✔️reciprocals and an inverse relationship
when period increases - ✔️✔️frequency decreases
When period decreases - ✔️✔️frequency increases
when period is unchanged - ✔️✔️frequency is also unchanged
when dealing with frequency and period remember to use units of - ✔️✔️sec & Hz
three bigness parameters - ✔️✔️amplitude, power, intensity
amplitude, power, and intensity describes a sound beams - ✔️✔️strength
amplitude, power, and intensity can all be changed by the sonographer and -
✔️✔️decreases as sound travels
amplitude, power, and intensity are initially determined by - ✔️✔️the sound source
amplitude is - ✔️✔️the difference between the average value and the maximum value
of an acoustic variable. The variation of an acoustic variable.