Please show work and explain. Answer is given already. Thank You. Light in one m
ID: 1302189 • Letter: P
Question
Please show work and explain. Answer is given already. Thank You. Light in one medium (n 1.2) encounters a boundary to a second medium (with n2 1. 8) where part of the light is transmitted into the second media and part is reflected back into the first media. The incident angle is 1 16 measured WITH RESPECT TO THE BOUNDRY (as shown in the picture). ni 1) What is the reflected angle $3 measured WITH RESPECT TO THE BOUNDRY as shown? 2) What is the refracted angle p2 measured WITH RESPECT TO THE BOUNDRY as shown? 3) How does the speed of light in the two materials compare? a the speed is greater in medium 1 b the speed is greater in medium 2 the speed is the same tical angle between the twoExplanation / Answer
(1)
As per laws of reflection, incident angle and reflected angle remain the same.
(2)
Using snell's law
sin(90 - phi 1)/ sin(90 - phi 2) = n2 / n1 = 1.8 / 1.2 = 1.5
cos(phi 1)/ cos(phi 2) = n2 / n1 = 1.8 / 1.2 = 1.5
phi 2 = cos-1(cos(16) / 1.5) = 50
(3)
Speed is greater in medium 1 because refractive index is lesser
n1 / n2 = v2 / v1
(4)
sin(90 - phi 1)/ sin(90 - phi 2) = n2 / n1 = 1.8 / 1.2 = 1.5
for Critical angle:
phi 1 = 0
1 / cos (phi 2) = 1.5
cos (phi 2) = 2/3
phi 2 = 48 deg
Critical angle = 90 - phi 2 = 42 degree