Many large and small rocks are found under glaciers. Explain how these rocks are both weathered and eroded.

Explanation below

Explanation:

Ice, mostly in the form of glaciers can create different landforms as it erodes the earth. In some areas with mountains, the glaciers move gradually downhill and across the land areas. When they move, the transport virtually everything on their path, ranging from small grains of sands to huge boulders.  

As these glaciers flow, the rocks being carried in the process scrape against the ground and erode both the ground and the rocks. Rocks are being ground up and oils are scrapped away.  

The main types of erosion created by the glaciers are abrasion and plucking.  

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.