Snell's Law for Light and Sound

Click For Summary

Homework Help Overview

The discussion revolves around the refraction of light and sound as they enter a liquid at a specified angle. The problem involves applying Snell's Law and understanding the relationship between speed and refractive index in different media.

Discussion Character

  • Conceptual clarification, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the application of Snell's Law for both light and sound, questioning the assumptions made regarding angles and refractive indices. There is discussion about the relationship between speed and refractive index, with some participants attempting to clarify their understanding of these concepts.

Discussion Status

Participants are actively engaging with each other's reasoning, with some providing corrections and clarifications regarding the use of angles and the relationship between speed and refractive index. There is a mix of interpretations and attempts to reconcile differing views on the problem setup.

Contextual Notes

There is a noted distinction between the information given for sound (speed) and light (refractive index), which some participants are attempting to reconcile in their calculations. The original poster expresses confusion about the angles involved, indicating a potential misunderstanding of the problem's parameters.

sparkle123
Messages
172
Reaction score
0
A laser beam and a sound wave from directional sources both enter a liquid at an angle of 60 degrees from the horizontal surface of the liquid. The speed of sound in the liquid is 1.8 times that of the speed of sound in air. For light, the refractive index of the liquid is 1.8. What happens?

Solution: The light refracts to an angle of 74° from the horizontal and the sound refracts to an angle of 26° from the horizontal.

I get that the beam and sound wave refract by the same amount since that both have a refractive index of 1.8 for the liquid. Also, my angle is different --> I get 69 degrees from the horizontal.
basically sin (40) = 1.8 sin (θ)
θ=21
 
Physics news on Phys.org
If you are going to use the conventional equations in refraction then the angles should from the NORMAL... have you done that?
You should also read the information very carefully.
In one case they have given you speed information and in the other case they have given you a 'refractive index'... do you know the link between speed and refractive index?
 
Yes, I did use the normal angles. I though speed is proportional to refractive index, like
v1/v2=n1/n2
 
Hey sparkle123!

Speed is inversely proportional to refractive index.

And if the angle with the horizontal is 60 degrees, I'm afraid the angle with the normal is not 40 degrees...
 
Wow I'm being awfully stupid! Thanks so much technician and I like Serena! :D
 

Similar threads

Optics: refraction and reflection
  • · Replies 1 ·
Replies
1
Views
2K
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
Solve Snell's Law: Glass Cube Refractive Index = 1.77
  • · Replies 8 ·
Replies
8
Views
6K
Applying Snell's Law Inside & Outside a Prism
  • · Replies 2 ·
Replies
2
Views
2K
How to Apply Snell's Law Without Knowing the Index of Refraction?
  • · Replies 4 ·
Replies
4
Views
2K
Calculating Index of Refraction with Wavelength
  • · Replies 1 ·
Replies
1
Views
2K
Snell's law experiment with glass block
  • · Replies 5 ·
Replies
5
Views
31K
Graduate Interpretation of a complex angle of refraction
  • · Replies 1 ·
Replies
1
Views
2K
What Angle Does Light Emerge from a Prism?
  • · Replies 4 ·
Replies
4
Views
3K