(a) what is the unit vector pointing from the origin to the diagonally opposite corner at location < 7.9, 7.9, 7.9 > cm? (express your answer in vector form.)

0.58, 0.58, 0.58

Explanation:

Given vector, a = (7.9, 7.9, 7.9)

Unit Vector,

The magnitude

                     |a| = 13.68

The unit vector is (0.58, 0.58, 0.58)          

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.