Question

beam of light, traveling in air(the index of refraction for air is 1), strikes the surface of mineral oil at an ngle of 30° with the normal to the surface.( the index of refraction for this mineral oil is 1.38) What is the ngle of refraction? What is the speed of the light traveling in mineral oil?

Answer 1

Answer:

2.17 x 10^8 m/s

Explanation:

Angle of incidence, i = 30 degree, refractive index of mineral oil, n = 1.38

Let r be the angle of refraction.

By use of Snell's law

n = Sin i / Sin r

Sin r = Sin i / n

Sin r = Sin 30 / 1.38

Sin r = 0.3623

r = 21.25 degree

Let the speed of light in oil be v.

By the definition of refractive index

n = c / v

Where c be the speed of light

v = c / n

v = ( 3 x 10^8) / 1.38

v = 2.17 x 10^8 m/s