Question

Use the exact values you enter to make later calculations.

A ray of light strikes a flat, 2.00-cm-thick block of glass (n = 1.57) at an angle of ? = 31.2

Answer 1

Note that from Snell's law,          
          
n1sin(t1) = n2sin(t2)          
          
where          
          
n1 = index of refraction of first medium =    1      
t1 = angle of incidence =    31.2   degrees  
n2 = index of refraction of second medium =    1.57      
t2 = angle of refraction          
Thus,          
          
t2 =    19.26595371   degrees   [ANSWER, PART A]

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The refracted angle at the bottom is just the same as the initial angle,

Ar = 31.2 degrees   [ANSWER]

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c.

d = 2.00 cm / cos (19.2659) * sin(31.2 - 19.2659)

Thus,

d = 0.4381 m   [ANSWER]

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v = c / n

Thus,

v = 1.91*10^8 m/s   [ANSWER]

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The distance it travelled there is

L = 2.00 cm / cos 19.2659 = 0.0211865 m

Thus, the time of travel is

t = n L / c = 1.11*10^-10 s   [ANSWER]