physics review

Question 1

Same as normal incidence

Answer 1

perpecndicular

orthoganal

right angle

ninety

normal

Question 2

other than 90° angle

Answer 2

oblique

Question 3

angle less than 90°

Answer 3

acute

Question 4

angle more than 90°

Answer 4

obtuse

Question 5

intensity right before striking a boundry

Answer 5

incident intensity

Question 6

portion of incident intensity reflected

Answer 6

reflected intensity

Question 7

normal incidence intensity that strieks boundry and returns

Answer 7

reflection

Question 8

normal incident intensity that continues after striking boundry

Answer 8

transmission

Question 9

normal incident intensity % that is reflected

Answer 9

Intensity relfectoin coefficient

IRC

Question 10

normal incident intensity that is transmitted

Answer 10

Intenity transmission coefficient

ITC

Question 11

units of IRC/ITC

Answer 11

%

Question 12

large relfection is impedance is

Answer 12

different

Question 13

with > impedance difference, IRC increases

what happens to the reflection?

Answer 13

increases

Question 14

specular reflection

Answer 14

reflection from a smooth surface

Question 15

oblique incidence

Answer 15

incidence other than 90°

Question 16

what 2 physical priciples apply to reflect with oblique incidence?

Answer 16

conservatoin of eneryg

reflection angle=indident angle

Question 17

transmission with a bend

Answer 17

refraction

Question 18

what is snells law?

Answer 18

quantifies the physics of refractoin

sine(transmission angle)/sin(incident angle)=speed of medium 2/speed of medium 1

Question 19

what media has greater attentuation and slower speed?

Answer 19

air

bone

lung

Question 20

what media has less attenuatin and greater speed

Answer 20

water

blood

urine

biologic fluids

Question 21

reflectoin from a rough surfaceis

Answer 21

diffuse

backscatter

Question 22

considered domionate to attenuation

Answer 22

absorption

Question 23

path length increases attenuationincrease/decrease?

Answer 23

increase

Question 24

characteristics of impedance

Answer 24

acoustic resistance to sound traveling in medium

calculated by densityxspeed

directly related to mediums density and speed

units rayls (Z)

acoustic impedance also called characteristic impdedance

Question 25

what needs to be present for reflections to occur?

Answer 25

a difference in impedance

Question 26

probe difference for small parts vs abdominal

Answer 26

small parts higher freq

abdomen lower frequence

Question 27

path length increases what happens to the atten coefficient

Answer 27

stays the same

coefficient affected only by the medium

Question 28

attenuation coefficient in soft tissue

Answer 28

.5dB/cm/MHz

Question 29

how is total attentuation determined

Answer 29

attenuation = atten coefficient x distance

Question 30

who is attenuatoin in soft tissue determined

Answer 30

attenuation coefficient = freq (MHz)/2

Question 31

for each 3dB increase what does the singnal increase

Answer 31

it doubles

Question 32

if something increases by 9db how much is the signal increase

Answer 32

2 x 2 x 2=8times

Question 33

higher frequency and longer path length more/less attenuation

Answer 33

more attenuation

Question 34

lower frequency and shorter path length means more/less attenuation

Answer 34

less attenuation

Question 35

sound scattering in all directions

Answer 35

rayleigh scattering

omni-directional

Question 36

rayleigh scattering is equal to

Answer 36

freq^4