Which statements are true about writing down your goals? Writing down your goals is motivating.
It is not really important to write down your goals.
Writing your goals helps you be more specific.
Writing goals wastes valuable workout time.
Writing goals helps clarify what results you are working towards.

Writing down your goals is motivating.

Writing your goals helps you be more specific.

Writing goals helps clarify what results you are working towards.

These are all true.

Explanation:

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.