A plane flies from base camp to Lake A, 280 km away in the direction 20.0∘north of east. After dropping off supplies, it flies to Lake B, which is 190 km at 30.0∘west of north from Lake A. Graphically determine the distance and direction from Lake B to the base camp.

i was thinking more like reflects green light, just not sure

it doesn't. it was imagined up in the middle ages.

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.