Question

1.a. How long (in ns) does it take light to travel 1.0 m in vacuum?

b. What distance does light travel in water, glass, cubiczirconia during the time it travels in 1.0m vacuum?

Answer 1

distance moved S = 1 m
speed of light in vaccum c = 3 * 10 ^ 8 m / s

So, required time t = S / c

                             = 0.3333 * 10 ^ -8 s

                              =3.333 ns

(b). speed of light in water v = c / n

where n = index of refraction of water = 4 / 3

So, v = 2.25 * 10 ^ 8 m / s

So, distance travel in water S ' = v t

                                              = 0.75 m

(c). speed of light in glass v = c / n

where n = index of refraction of glass = 1.5

So, v = 2 * 10 ^ 8 m / s

So, distance travel in water S ' = v t

                                              = 0.67 m