The mass of 2 cm3 of gold is 38.6 grams. find the density of the gold. could you me? ?

Density = mass/ volume (so here this is how you would solve the problem)

D = 38.6 g/ 2 cm3 (first step)

D= 19.3 g/cm3  ( Do math and then you would get this)

Hope this helps!! :) 

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.