reflection and transmission of soundwaves

bulk modulus

the decrease in ratio between stress (change in pressure) and strain (percent of volume change when stress is applied)

incidence

refers to the angle at which the sound beam strikes the medium/boundary

what are the 2 types of incidence?

normal and oblique

normal incidence (perpendicular, orthogonal, right angle, 90 degrees)

sound strikes the boundary at 90 degrees

oblique incidence

the sound strikes the boundary at any angle that is not a right angle, so acute or obtuse angles

incident intensity

the wave’s intensity before it strikes a boundary

reflected intensity

the intensity of the wave as it returns back to the transducer after striking the boundary

transmitted intensity

the intensity of the wave as it continues forward in the same direction after striking the boundary

intensity reflection coefficient

percentage of the intensity that bounces back when a sound beam strikes the boundary between 2 media

intensity transmission coefficient

percentage of intensity that passes in the forward direction when the bream strikes an interface between 2 media

what two physical principles always apply in cases of oblique incidence?

• conservation of energy

• reflection angle = incident angle

refraction

transmitted portion of a sound beam bends or changes direction at an interface between 2 different media

refraction only occurs if what 2 conditions are satisfied?

• oblique incidence angle

• different propagation speeds of the 2 media

Snell’s law

quantifies the physics of refraction