Physics Formulas

Question 1

Period (T) (µs)

Answer 1

Period (T) = 1/frequency

Question 2

Wavelength (lambda)(mm)

Answer 2

Wavelength (mm) = propagation speed (mm/microsecond)/frequency (MHz)

Question 3

Power (W)(mW)

Answer 3

Power (mW) = Amplitude (A) squared (dB)

Question 4

What is the Power with 1/2 Amplitude

Answer 4

Power (mW) = 1/4
[A= 1/2 (square denominator)]
[A= 1/3 (P= 1/9)]

Question 5

Intensity (I) [(m)W/cm squared]

Answer 5

Intensity = Power/Area

Question 6

Beam Uniformity Ratio (BUR)

Answer 6

BUR = SP/SA (Spatial Peak/Spatial Ave.)

Question 7

Impedance (Z)(rayl)

Answer 7

Impedance = Density (kg/m cubed) x propagation speed (m/s)

Question 8

Intensity Reflection Coefficient (IRC)

Answer 8

IRC = [(Z2-Z1)/(Z2+Z1)] squared

Question 9

Intensity Transmission Coefficient (ITC)

Answer 9

ITC = 1-IRC

Question 10

Reflected Angle always equals what?

Answer 10

Incidence Angle

Question 11

Attenuation Coefficient (dB/cm)

Answer 11

Attenuation Coefficient = 0.5 x frequency (MHz)

Question 12

Total attenuation (dB)

Answer 12

Total attenuation = 0.5 x frequency x path length

Question 13

Quality Factor (Q factor)

Answer 13

Q factor = Operating frequency/Bandwidth

Question 14

1 Near Zone Length

Answer 14

1 Near Zone Length = 1/2 transducer diameter

Question 15

Axial Resolution (mm)

Answer 15

Axial Resolution = spatial pulse length/2

Question 16

Elevational Resolution

Answer 16

Elevational Resolution = Beam thickness

Question 17

Range Equation (Distance to Reflector) (mm)

Answer 17

Range (Distance) = 1/2 x (propagation speed x pulse round-trip time)

Question 18

Abbreviated Range Equation

Answer 18

Range (D) = 1/2 CT [Constant Time (Propagation Speed)]

Question 19

Nyquist Limit

Answer 19

Nyquist Limit = PRF/2

Question 20

Pulse Repetition Frequency (PRF)(kHz)

Answer 20

PRF = 1/PRP (ms)
or
PRF = lines per frame x frame rate (Hz)

Question 21

Pulse Repetition Period (PRP)(ms)

Answer 21

PRP = 1/PRF (kHz)

Question 22

Pulse Duration (PD)(µs)

Answer 22

PD = # of cycles in a pulse x period (T)

Question 23

Spatial Pulse Length (SPL)(mm)

Answer 23

SPL = # of cycles in a pulse x wavelength

Question 24

Duty Factor (DF)

Answer 24

DF = PD/PRP

Question 25

Shades of Gray

Answer 25

Shades of Gray = 2ª (a=x) | 4 bit = 2x2x2x2= 16 shades of gray

Question 26

Binary Code uses what values? How would you write 17?

Answer 26

1,2,4,8,16,32,(doubles); 17 = 1 0 0 0 1

Question 27

Doppler Shift

Answer 27

Doppler Shift = (2 x velocity (RBC) x transmit frequency x Cos of angle)/ C (propagation speed) RBC=Red Blood Cell Cos=Cosine C=Constant

Question 28

T

Answer 28

Period

Question 29

Lambda

Answer 29

Wavelength

Question 30

A

Answer 30

Amplitude

Question 31

P

Answer 31

Power

Question 32

I

Answer 32

Intensity

Question 33

BUR

Answer 33

Beam Uniformity Ratio

Question 34

Z

Answer 34

Impedance

Question 35

IRC

Answer 35

Intensity Reflection Coefficient

Question 36

ITC

Answer 36

Intensity Transmission Coefficient

Question 37

dB

Answer 37

decibels

Question 38

Q factor

Answer 38

Quality Factor

Question 39

LARRD

Answer 39

Axial Resolution (Longitudinal, Axial, Range, Radial, Depth)

Question 40

LATA

Answer 40

Lateral Resolution (Lateral, Angular, Transverse, Azimuthal)

Question 41

PRF

Answer 41

Pulse Repetition Frequency

Question 42

PRP

Answer 42

Pulse Repetition Period

Question 43

PD

Answer 43

Pulse Duration

Question 44

SPL

Answer 44

Spatial Pulse Length

Question 45

DF

Answer 45

Duty Factor