Reflection and Refraction formula help

Click For Summary

Homework Help Overview

The discussion revolves around the concepts of reflection and refraction, specifically focusing on the application of Snell's law in a problem involving angles of incidence and refraction.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to apply Snell's law using an initial assumption about the angle of incidence, which is later questioned by participants. There is a discussion about the correct interpretation of the angle of incidence, with various angles proposed by different participants.

Discussion Status

Participants are actively engaging in clarifying the definition of the angle of incidence and correcting misunderstandings. Some guidance has been provided regarding the relationship between the angle of incidence and the surface normal, indicating a productive direction in the discussion.

Contextual Notes

There appears to be confusion regarding the correct angle of incidence, which is central to applying Snell's law accurately. Participants are exploring different interpretations of the problem setup.

Muhammad Danish
Messages
70
Reaction score
7

Homework Statement


upload_2018-4-17_0-34-37.png

2. Homework Equations

3. The Attempt at a Solution [/B]
I tried to solve this question with the general formula n=sin i / sin r. 1.5 = sin 30/sin r,
r = 19.4 = 19 which is option A. But option A is incorrect. Please guide me where am I wrong..
 

Attachments

  • upload_2018-4-17_0-30-48.png
    upload_2018-4-17_0-30-48.png
    9.4 KB · Views: 640
  • upload_2018-4-17_0-34-37.png
    upload_2018-4-17_0-34-37.png
    8.1 KB · Views: 2,036
Physics news on Phys.org
The incident angle is not 30 degrees.
 
  • Like
Likes   Reactions: Muhammad Danish
Orodruin said:
The incident angle is not 30 degrees.
60 degrees??
 
Muhammad Danish said:
50 degrees??
Why would it be 50 degrees?
 
Orodruin said:
Why would it be 50 degrees?
Sorry I mean't 60 degrees, since 90-30 = 60
 
Muhammad Danish said:
Sorry I mean't 60 degrees, since 90-30 = 60
Yes, the incident angle is the angle between the surface normal and the ray, not between the surface itself and the ray.
 
Orodruin said:
Yes, the incident angle is the angle between the surface normal and the ray, not between the surface itself and the ray.
Thanks a lot for pointing that mistake out. I was making the same mistake in many questions like that.
 

Similar threads

Glass prism and its refractive index
  • · Replies 1 ·
Replies
1
Views
2K
The refractive index of an unknown liquid
  • · Replies 1 ·
Replies
1
Views
3K
Optics: refraction and reflection
  • · Replies 1 ·
Replies
1
Views
2K
Calculate a radius of a circle on a screen
  • · Replies 3 ·
Replies
3
Views
1K
Optical path difference between two reflected rays
  • · Replies 4 ·
Replies
4
Views
958
Finding the angle of refraction
  • · Replies 11 ·
Replies
11
Views
7K
How to find unknown refractive index to solve for theta
  • · Replies 11 ·
Replies
11
Views
3K
Refraction: object disappearing in liquid
  • · Replies 15 ·
Replies
15
Views
3K
When can internal reflection be used to find the index of refraction
  • · Replies 4 ·
Replies
4
Views
2K
Solve Snell's Law: Glass Cube Refractive Index = 1.77
  • · Replies 8 ·
Replies
8
Views
6K