The surface area of the earth's crust is 5.10*10^8km^2. the average thickness of the earth's crust is 35km. the mean density of the earth's crust is 2.8g/cm^3. the most abundant element in the earth's crust is oxygen with an abundance of 4.55*10^3g/t. calculate the total volume of the earth's crust.

The answer is .

Explanation:

You are asking only for the total volume, so the important data here is the surface area of the earth's crust,

and the average thickness of the earth's crust,

.

Imagine that you can stretch the surface area as if it were a blanket, now if you want to calculate its volume, you just need to multiply its area by its thickness,

.

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.

you get 2.3=1.21*\frac{a}2 or 4.6=1.21a or a=3.802 (b)

explanation: