Concave Lens Equation Derivation: Understanding the Role of Refractive Index

  • Thread starter Thread starter Daniiel
  • Start date Start date
  • Tags Tags
    Derivation
AI Thread Summary
The discussion centers on the derivation of the concave lens equation, specifically addressing discrepancies in the results obtained by different individuals. The user notes that their solution for the image distance (i) differs from the provided solution, particularly in the treatment of the refractive index (n2). They express confusion over how n2 was canceled in the solution they compared against. The problem involves a concave lens scenario with specific values for n1 and n2, leading to a formula that needs simplification to find i. Clarification on the cancellation of n2 is sought to resolve the differences in the calculations.
Daniiel
Messages
119
Reaction score
0
Hey
this is a pretty straight forward equation derivation, but when i do it and compare it to the solutions, mine is different to theirs.
The equation is
[PLAIN]http://img213.imageshack.us/img213/9790/ddaaad.jpg where n1=1
for a concave lens (fish in a fish bowl) so r is negative

solving for i

they get, r/(n2+1)

and i get n2r/(n2+1)

there answer seems right for the question, but I am just not sure how they canceled the n2
 
Last edited by a moderator:
Physics news on Phys.org
Post the actual problem in the book.
 
[PLAIN]http://img228.imageshack.us/img228/593/dsdsdsaas.jpg

p = r/2 n2 = water
 
Last edited by a moderator:
The fish is inside the bowl. So the formula becomes

n1/p + n2/i = (n1 - n2)/r

Here n1 = 1.33 and n2 = 1.

Now simplify and find i.
 
oh right
thanks alot
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Similar threads

Lens with different refraction index on each side
Replies
7
Views
2K
Lens Maker's Formula - Confusion in the derivation
Replies
15
Views
1K
Calculate the focal distance of the duplicate
Replies
3
Views
1K
Index of refraction for converging lens
Replies
3
Views
2K
Image distance from the hemisphere lens
Replies
9
Views
2K
What Condition Ensures Refracted and Incident Rays Have the Same Direction?
Replies
4
Views
1K
Lens-Makers Equation: Finding Focal Length in Different Mediums
Replies
2
Views
3K
Find index of refraction of a sphere given the beam path
Replies
1
Views
4K
Law of Refraction with changing index of refraction
Replies
2
Views
2K
Find magnification of a fish in a fish bowl
Replies
1
Views
4K

Hot Threads

Recent Insights

Back
Top