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:

 $T = \frac{15}{f}$

Step-by-step explanation:

Given:

Thickness og glass = L

Index of refraction n=1.5

Frequency = f

$Wavelength = \frac{L}{10}$

λ(air) $= \frac{L}{10}$

λ(glass) = λ(air) / n

             = $\frac{\frac{L}{10}}{1.5}$

             = $\frac{L}{10} * \frac{1}{1.5}$

             = $\frac{L}{15}$

V(glass) = fλ(glass)

              $= f * \frac{L}{15}$

          $T = \frac{L}{V_{glass}} = \frac{15}{f}$