When two waves in the same medium hit each other, the resulting displacement of the medium is
1. either larger or smaller than the displacement of either wave acting alone, depending on the signs of the displacements of the two waves.
2. always larger than the displacement due to either wave acting alone.
3. always smaller than the displacement due to either wave acting alone.

1. Either larger or smaller than the displacement of either wave acting alone, depending on the signs of the displacements of the two waves.

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop

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.