Ultrasound Physics Ch 1 & 2

Unrelated

two items not associated

Directly related

one specific item increases, the other increases

Related

items associated but don’t have to be specific

Inversely related

one item increases, one item decreases

Multiply

Increases by a factor

Divide

Decreases by a factor

Unitless

Percent is ________.

Total picture

When units change, the “_____________” does not change

1-10

A number with an exponent of zero has a value of ______.

Giga (G)

10⁹

Mega (M)

10⁶

Kilo (K)

10³

Hecto (H)

10²

Deca (Da)

10¹

Deci (d)

10^-1

Centi (c)

10^-2

mili (m)

10^-3

micro

10^-6

nano

10^-9

Miliseconds

If frequency is megahertz then period is ________.

1/20

Reciprocal of 20

Directly related

The graph goes from lower left to upper right

Inversely related

The graph goes from upper left to lower right

Energy

Waves carry ______.

Heat, sound, magnetic, light

Types of waves

Mechanical/longitundinal

Sound is a ______ wave.

Acoustic variables

Allows us to DETERMINE between sound waves and other types of waves

Pressure, density, distance, temperature

Types of acoustic variables

Pressure (Pa)

concentration of force in an area

Density (kg/cm³)

concentration of mass in a volume (mass/volume)

Distance (cm, mm, ft, mi)

measure of particle motion (move parallel to a wave)

Temperature

Energy is lost to heat within the medium

Compression

high pressure and high density (particles are close together/above baseline)

Rarefaction

low pressure and low density (particles are far apart/below the baseline)

has rhythmic oscillation

Sound waves occur when one of the acoustic variables ______.

Period, frequency, amplitude, power, intensity, wavelength, propagation speed

Describe and measure the wave’s feature

In phase wave

pair of waves peaks/troughs occur at same time and same location

Out of phase

peaks and troughs occur at different times

Interference

when two waves combine to form a single wave

Constructive interference

two in-phase waves result in a bigger wave

Destructive interference

two out of phase waves result in a smaller wave