What is the intensity of the incident of light?

  • Thread starter Thread starter phy112
  • Start date Start date
  • Tags Tags
    Intensity Light
AI Thread Summary
The discussion revolves around calculating the intensity of incident light on a system of three polarizers. The second polarizer is at a 28.0° angle to the first, and the third is at a 45.0° angle to the first. The emerging light intensity is given as 2.1 W/m². Participants clarify the calculations needed, noting a common mistake regarding the angle between the second and third polarizers. The conversation emphasizes the importance of correctly applying the polarizer intensity equations and factors.
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.)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

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

Hot Threads

Recent Insights

Back
Top