Reflection/Refraction homework help

[3gowns]

Homework Statement

A light ray is incident on a glass prism with n=1.65. (A) If the prism is immersed in air, where does the light ray emerge into the air? At what angle? (B) If the prism is immersed in water, where does the light emerge into the water? At what angle?

_____ A_____C
_____ |90 45/
_____ |____/
----->|___/
_____ |n /
_____ B /

Homework Equations

n_a sin(theta_a) = n_b sin(theta_b)
sin(theta)critical= n_b/n_a

The Attempt at a Solution

PART A:

AB)
1.0 sin(0)= 1.65 sin(theta)'
(theta)'= 0 (no bending)

BC) (crtitical angle 41.1 in air?)
1.65 sin 45 = 1.52 sin (theta)'
(theta)'= 50.14 <- final answer

PART B:
just change the n's?

Any good?

 

[mgb_phys]

B, yes n for water is around 1.3

 

[baba89]

I would like to commend you for showing your work and using the correct equations to solve the problem. Your solution for Part A is correct, as the light ray would not bend when entering the air since the incident angle is 0 degrees. However, for Part B, you would need to use the equation n_a sin(theta_a) = n_b sin(theta_b) to solve for the angle at which the light emerges into the water. The critical angle for water is approximately 48.6 degrees, so the final angle would be greater than that. Keep up the good work!