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131 Cards in this Set
- Front
- Back
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What is mathematics?
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Mathematics is a collection of disciplines.
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When reciprocals are multiplied the product is ____.
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One
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A letter which represents a physical quantity is a ____.
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Variable
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Raising a number to a power is a ________.
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Short hand notation for multiplication.
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What does a negative exponent tell you?
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It tells you how many times to use the reciprocal of the base as a factor
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What is exponential notation?
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It's the use of powers of 10 to simplify large and small numbers.
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______ is a relationship between variables in which one variable increases, and the other also increases.
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proportionality
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What is linear proportionality?
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When one variable increases by a % the other variable also increases by the same %
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What is inverse proportionality?
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The relationship between variables in which one increase, the other variable decreases
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Who invented the metric system?
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french scientists in the 18th century
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What was the original definition of the meter?
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Distance from the north pole to equator divided into 10 million
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The modern definition of the meter is...
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distance light travels in a vacuum in 1/299 792 458 second.
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What is the speed of light?
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300,000 km/sec or 300 mega meters/sec
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The circumference of the earth is _____.
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40 Mega meters
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One inch is equal to how many cm?
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2.54 cm
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Giga (G)
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10^9
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Mega (M)
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10^6
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Kilo (K)
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10^3
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Hecto (h)
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10^2
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Deca (da)
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10^1
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Deci (d)
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10^-1
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Centi (c)
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10^-2
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Milli (m)
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10^-3
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Micro(u)
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10^-6
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Nano (n)
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10^-9
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What is the variable for time & how is it measured?
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The variable is (t) and it is measured in seconds
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The variable for frequency is ____ and it is measured in _____
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(f) and it is measured in hertz
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Length's variable is ____ and is measured in _____
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(l) and it is measured in meters
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The variable for velocity is ___ and is measured using ____
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(v) or (c) and is measured in meter per second
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What is the variable for acceleration and how is it measured?
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(a) and is measured in meter per second squared
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The variable for mass is ____ and is measured using ____.
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(m) measured using kilograms
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The variable for force is ____ and its measured using ____
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(f) measured using newtons
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What is the variable for impulse? How is it measured?
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(i) measured in newtons x second
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Work, also known as energy is measured in _____. Its variable is....
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Measured in joules which = one newton x meter. Variable is (w)
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Power's variable is ____ and is measured using...
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(W) measured using watt which = one joule per second
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1 Kg equals how many lbs?
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2.204 lb
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1 lb equals how many Kg?
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.45 Kg
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1 Kg equals how many lbs?
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2.204 lb
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1 Mile equals how many Km?
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1.6 Km
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1 lb equals how many Kg?
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.45 Kg
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1 liter equals how many mililiters?
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1000 ml
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1 Mile equals how many Km?
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1.6 Km
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1 liter equals how many mililiters?
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1000 ml
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One calorie is equal to approximately _____ joules.
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4.186 joules
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_____ is the transmission of _____ vibrations through a medium
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sound,mechanical
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One calorie is equal to approximately _____ joules.
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4.186 joules
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_____ is the transmission of _____ vibrations through a medium
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sound,mechanical
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How is sound produced?
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By vibrating a source
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How is sound produced?
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By vibrating a source
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What does the vibration of the source cause?
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It causes particles in the medium to oscillate (vibrate) back & forth
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1 Kg equals how many lbs?
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2.204 lb
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What is simple harmonic motion (sinusoidal)?
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sound produced by a vibrating source that oscillates back in forth along a line
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What does the vibration of the source cause?
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It causes particles in the medium to oscillate (vibrate) back & forth
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1 lb equals how many Kg?
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.45 Kg
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What is simple harmonic motion (sinusoidal)?
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sound produced by a vibrating source that oscillates back in forth along a line
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Sound is a ____ wave.
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Pressure
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1 Mile equals how many Km?
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1.6 Km
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1 liter equals how many mililiters?
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1000 ml
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Sound is a ____ wave.
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Pressure
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One calorie is equal to approximately _____ joules.
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4.186 joules
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_____ is the transmission of _____ vibrations through a medium
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sound,mechanical
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How is sound produced?
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By vibrating a source
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What does the vibration of the source cause?
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It causes particles in the medium to oscillate (vibrate) back & forth
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What is simple harmonic motion (sinusoidal)?
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sound produced by a vibrating source that oscillates back in forth along a line
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Sound is a ____ wave.
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Pressure
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The vibration of a source causes a wave of _____ & _____ of particles
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compression & rarefactions
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Solids are better transmitters than _____.
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liquids
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Liquids are better transmitters than _____.
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Gases
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What is a wave?
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A wave is a mechanism which transfers energy, not matter
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A wave with a repetitious source transfers energy in a ______ manner
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cyclical
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Mechanical waves need a ____ to propagate.
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Medium, example is sound
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Electromagnetic waves propragate in a ____ or ____.
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medium or vacuum
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Longitudinal waves propagate by _____ & _____
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particle compression & rarefaction
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Sound is a _____, _____,_____.
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Mechanical, longitudinal, compressional wave
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Transverse waves propagate by _____ and is ____ to the wave direction
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propagate by particle motion, transverse to the wave direction
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What are torsion waves?
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Waves produced by twisting of the particles of a medium about an axis
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Rayleigh waves are ____ waves that travel across the ____ of a medium
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transverse waves, travel across the surface
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An example of a Rayleigh wave is a _____
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water wave, rock tossed in water
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The amplitude of a Rayleigh wave pressure _____ with depth.
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decreases
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The 4 acoustic variable are ...
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pressure, density, temperature, and particle motion
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What is acoustic pressure?
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force of compression applied to a unit area of a medium by a sound wave
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When does acoustic pressure increase?
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During the compression phase of a sound wave
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The acoustic pressure decreases during the ____ phase.
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rarefaction
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What is the main unit used in ultrasound physics?
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Newton/cm^2
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Density is defined as...
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mass per unit volume
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_____ causes higher density, while ____ causes lower density.
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Compression causes higher, rarefaction causes lower
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What is the freezing temperature of water?
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0 degrees celsius (32 degree fahrenheit)
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What is the boiling temperature or water?
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100 degrees celsius (212 degrees fahrenheit
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What is the formula for temperature unit conversion?
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C F- 32
---- = --------- 100 180 |
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Temperature _____ during a compression.
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increases
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When does temperature decrease?
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during a rarefaction
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What are the 3 well-known temperature scales?
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Kelvin, Celsius, and Fahrenheit
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Which temperature scale is used in ultrasound physics?
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Celsius
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The normal human body temperature is ____.
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36.8 degrees C
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Sound waves carry ____ not _____.
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energy not matter
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The four sound wave characteristics are...
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frequency, period, wavelength, and propagation velocity
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What is frequency?
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a measure of how many times an event occurs per time
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What is sound wave frequency?
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The number of oscillations per second performed by the medium
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What is frequency determined by?
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The source of sound
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The # of cycles of increase & decrease that acoustic variable goes through in one second is _____
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frequency
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The unit for frequency is ____.
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cycles per second =Hertz (Hz)
1 cycle per second = 1 Hz |
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What is the range of Hz for infrasound?
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0-20
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What is the range of Hz for audible sound?
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20 Hz-20 KHz
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Ultrasound frequencies are greater than...
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20 KHz
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The hertz for diagnostic ultrasound are ____.
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2 MHz-12MHz
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What is intravascular ultrasound?
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Transducer attached to the tip of a catheter inserted into a vessel to assess vessel walls for plaque
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Time needed to complete one cycle is considered a ____.
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Period (T)
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Period and ____ are reciprocals.
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frequency
T= 1/F |
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Period is determined by the _____ .
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Source of sound
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What are the units used to measure period?
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sec, msec and usec
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What is the range of periods in diagnostic ultrasound?
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.08 - .5 usec
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The physical distance one cycle occupies is...
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the wavelength for a sound wave
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Wavelength is determined by both the ____ & the _____.
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source and the medium
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The units used to measure wavelength are...
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m, cm, and mm
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Wavelength and Frequency are _____ related.
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Inversely
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What is the propagation velocity of sound?
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The distance sound can travel per unit of time determined by the medium
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The propagation velocity depends on...
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the physical properties of the medium
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Sound travels the fastest in ____.
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Bone
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The average speed of sound in soft tissue is _____.
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1540 m/sec
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What 2 things is wavelength affected by?
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Frequency and propagation
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True or False. Wavelength and propagation velocity are proportional.
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true
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Wavelength and frequency are _____ proportional.
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inversely
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The three properties of ultrasound waves are...
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Amplitude, Power, and Intensity
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The maximum variation of an acoustic variable from its mean value is _____
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amplitude
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The rate at which work is performed or energy is transferred is _____.
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Power
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The equation for power is...
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Power = energy(work) / time
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What is the unit for power?
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Watt
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_____ is the concentration of power per unit area.
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Intensity
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What is acoustic intensity?
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the concentration of power per unit area of the sound beam
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If power doubles while beam area remains the same what happens to intensity?
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It also doubles
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If amplitude doubles while beam area remains the same what happens to intensity?
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It increases 4 times
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