A70 kilogram mountaineer is standing on the summit of mt. everest. the distance between the mountaineer and the center of earth is 6.39 × 106 meters. what is the magnitude of the force of gravity acting on the mountaineer? (the value of g is 6.673 × 10-11 newton meter2/kilogram2. the mass of earth is 5.98 × 1024 kilograms.)

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.