Question

A:
Part 1. The speed of light is 3 × 108 m/s, the index of refraction of water is 1.33, and the index of refraction of glass is 1.5. Find the speed of light in water.

1. 1.66667 × 108 m
2. 3 × 108 m/s
3. 2.25564 × 108 m/s
4. 2.14286 × 108 m/s
5. 2 × 108 m/s
6. 1.5 × 108 m/s

Part 2. Find the speed of light in glass.
1. 1.66667 × 108 m/s
2. 2 × 108 m/s
3. 1.5 × 108 m/s
4. 3 × 108 m/s
5. 2.25564 × 108 m/s
6. 2.14286 × 108 m/s

B:

Light goes from flint glass into ethanol. The angle of refraction in the ethanol is 13.7 ? , the index of refraction for flint glass is 1.61, and the index of refraction for ethanol is 1.36. What is the angle of incidence in the glass? Answer in units of ? .

Answer 1

The speed of light in a medium is inversely proportional to the refractive index of the medium.

v=c/n, where,

v is the speed of light in a particular medium.

c=3x10⁸m/s is the speed of light in vacuum.

n is the refractive index of the medium.

A) speed of light in water = 3x10⁸ / 1.33

= 2.26x10⁸m/s

B)  speed of light in glass = 3x10⁸ / 1.5

= 2.0x10⁸m/s

C) angle of refraction in the ethanol ?e = 13.7^o

the index of refraction for flint glass n_g = 1.61

the index of refraction for ethanol ne = 1.36

using snell's law

n_g * Sin?g = ne * Sin?e;

Sin?g = (ne * Sin?e)/n_g

?g = 11.54^o.