So i know this is a lot to ask but i failed this test and i have a f and the quarter ends in like 2 weeks and i have no idea what i'm doing so if someone could me it would be really appreciated and also i have crossed out the ones i got right. and there might a few questions because it won't let me put more than one picture.

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.

higher potential

explanation:

because it is in a high speed so it must move into a of high potential