Question

A beam of light from a monochromatic laser shines into a piece of glass. The glass has thickness L and 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.

Answer 1

Additional information to complete the question:

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 some or all of the variables f and L. Use the numeric value given for n in the introduction.

T = ___________ s

Answer:

`T = (15)/(f)`

Explanation:

Given:

Thickness og glass = L

Index of refraction n=1.5

Frequency = f

`Wavelength = (L)/(10)`

λ(air)
`= (L)/(10)`

λ(glass) = λ(air) / n

=
`((L)/(10))/(1.5)`

=
`(L)/(10) * (1)/(1.5)`

=
`(L)/(15)`

V(glass) = fλ(glass)

`= f * (L)/(15)`

`T = (L)/(V_(glass)) = (15)/(f)`