Which is the best analogy of a wave? A wave is like building a ramp.
A wave is like shaking a hand.
A wave is like water rippling in a pond.
A wave is like knocking down a building.

A wave is like water rippling in a pond.

Explanation:

when explaining waves in schoolthey ALWAYS use this analogy, sorry its wrong, have a buttiful day <3 :p

spare some change and give it to the poor

explanation:

plz : ((

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.