3) A dust particle hovers in front of a silent loudspeaker (see below). The loud speaker is turned on and plays a loud tone at a constant pitch
Spel
Dutch
How will the dust particle move?
a. It will stay in the same position.
b. It will move right and left about the same position
it will move up and down about the same position,
d. It will move away from the speaker in a straight line.
It will move away from the speaker in circular movements.
e

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.