An object of volume has 20ml has a mass of 2.5kg what will be its density​

0.125

Explanation:

Density =mass/volume

Density =2.5/20

Density =0.125

D=m/v

=2.5kg/(20/1000000)m^3

2.5kg÷0.000002m^3

1250000kgm^-3

Explanation:

20 is divided by 1000000 because m^3 is its si unit

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.

i already answered it by 34/s