Complete Question:
A beam of light from a monochromatic laser shines into a piece of glass. The glass has thickness Land index of refraction n=1.5. The wavelength of the laser light in vacuum is L/10 and its frequency is f. In this problem, neither the constant c nor its numerical value should appear in any of your answers.
How long does it take for a short pulse of light to travel from one end of the glass to the other?
Express your answer in terms of the frequency, f. Use the numeric value given for n in the introduction.
Answer:
15/f
Step-by-step explanation:
Wavelength of the laser light, λ = L/10
Where L = Distance covered by the light
Refractive index, n = 1.5
Speed, v = λf
Since we are considering the laser light, the speed of light, c, will be used.
c = v
c = λf
c = (L/10)f
(L/10)f = L/t
f/10 = 1/t
t = 10/f
since the refractive index, n = 1.5
t = 1.5(10/f)
t = 15/f