Sunlight strikes a piece of crown glass at an angle of incidence of 38.6 o . Cal

Question

Sunlight strikes a piece of crown glass at an angle of incidence of 38.6o. Calculate the difference in the angle of refraction between a yellow (580 nm) and a green (550 nm) ray within the glass. The index of refraction is n=1.523 for yellow and n=1.526 for green light.

The ray now travels inside the glass. What is the minimum angle of incidence at which the yellow ray can hit the surface of the glass and become there totally internally reflected and not refracted?

You have to calculate the angle of refraction for both light rays (they have different indices of refraction). You are looking for the difference of these angles.

Explanation / Answer

1) n1*sin(theta 1)= n2*sin(theta 2) (this is the formula to use)

so for yellow: 1*sin (38.6)=1.523* sin (theta 2)
so 0.5798=1.523*sin (theta 2)
sin (theta 2)=0.5798/1.523
sin(theta)=0.3806 >>> to find theta (sin^-1 of 0.3806)= 22.37 degrees for yellow
for green same thing: 1*sin(38.6)=1.531*sin(theta 2)
0.5798=1.526*sin (theta 2)
sin(theta 2)= 0.5798/1.526
sin(theta 2)=0.3794>>>>> theta = sin^-1 of 0.3794= 24.77 degrees for green.
yellow - green= 22.37- 24.77=-2.4

2) sin i/sin90 = 1/1.523
i=44.48o
There for angle of incidence should be greater than 44.48o

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.