What is the intensity of the incident of light?

  • Thread starter Thread starter phy112
  • Start date Start date
  • Tags Tags
    Intensity Light
Click For Summary
SUMMARY

The discussion focuses on calculating the intensity of incident unpolarized light passing through a system of three polarizers, with specific angles of 28.0° and 45.0° between them. The final intensity after the polarizers is given as 2.1 W/m². The correct approach involves applying Malus's Law, which states that the transmitted intensity through a polarizer is proportional to the cosine squared of the angle between the light's polarization direction and the polarizer's axis. The solution requires careful consideration of the angles and the multiplication factor from the two polarizers.

PREREQUISITES
  • Understanding of Malus's Law in optics
  • Basic knowledge of trigonometric functions, specifically cosine
  • Familiarity with the concept of intensity in physics
  • Ability to perform calculations involving angles in degrees
NEXT STEPS
  • Study the application of Malus's Law in multi-polarizer systems
  • Learn how to calculate intensity changes in polarized light
  • Explore the effects of varying angles between polarizers on light intensity
  • Practice problems involving unpolarized light and polarizers
USEFUL FOR

Students studying optics, physics educators, and anyone interested in understanding the behavior of light through polarizing filters.

phy112
Messages
37
Reaction score
0

Homework Statement



Unpolarized light is incident on a system of three polarizers. The second polarizer is oriented at an angle of 28.0° with respect to the first and the third is oriented at an angle of 45.0° with respect to the first. If the light that emerges from the system has an intensity of 2.1 W/m2, what is the intensity of the incident light?


Homework Equations



is this what you do: 2.1W/m^2 divided by cos^2(21). then divide that answer by cos^2(28) than multiply that anwswer by 2? I can's eem to get the right anwser to cos2(21) and cos2(28) right in my calculator. I need some help

The Attempt at a Solution

 
Physics news on Phys.org
You're right except for the 21o. What is the angle between the 2nd and 3rd polarizers?

(Good job catching the final 2x factor, a lot of people miss that on problems like this.)
 

Similar threads

Effect of a polarizer/analyzer on partially polarized light
  • · Replies 25 ·
Replies
25
Views
4K
Intensity of light passing through 3 polarizers
  • · Replies 3 ·
Replies
3
Views
6K
Polarization of Light: Polarizer
  • · Replies 7 ·
Replies
7
Views
3K
Why Does Unpolarized Light Lose Half Its Intensity Through a Polaroid?
  • · Replies 4 ·
Replies
4
Views
2K
Intensity of light through two polarizers
  • · Replies 3 ·
Replies
3
Views
3K
Does light intensity change with two polarizing sheets?
  • · Replies 3 ·
Replies
3
Views
2K
Understanding Malus Law and Polaroid Intensity: Conceptual Doubts
  • · Replies 2 ·
Replies
2
Views
2K
Intensity of polarized light that has passed through two polarizing sheets
  • · Replies 19 ·
Replies
19
Views
7K
What is the intensity of light after removing the second polarizer?
  • · Replies 1 ·
Replies
1
Views
2K
Photoelectric exp - calculate intensity of incident light
  • · Replies 3 ·
Replies
3
Views
2K