# Finding final image through a lens

1. Sep 29, 2011

### coltin.walsh

1. The problem statement, all variables and given/known data

An object is situated at various points relative to V. The light is then reflected by the mirror, and the final image is viewed by the observer.

http://www.flickr.com/photos/55153239@N03/6196518731/ [Broken]

2. Relevant equations

1/s + 1/s' = 2/R
na/s + nb/s' = (nb-na)/R

3. The attempt at a solution

The final statement of the problem confused me. It says the final image is viewed from the left of the figure. Therefore, you the mirror create an image inside the lens, and the light would then be refracted to the viewer outside the lens?

for d) I used the second equation to refract the light into the lens, to get s' = -3/2 R. This then acts as the object for the mirror a distance 5/2 R. Using the first equation, i get s' = 5/8 R. This would act as the object for the second refraction outside the lens. the end result is R/4 to the right of V. Is that correct?

Last edited by a moderator: May 5, 2017
2. Sep 30, 2011

### rl.bhat

Hi coltin.walsh, welcome to PF.
"This would act as the object for the second refraction outside the lens. the end result is R/4 to the right of V."
Check this last step. Show your calculation.

3. Sep 30, 2011

### coltin.walsh

so i would have s = 3/8 R. and using the second equation:

1.5/(3R/8) + 1/s' = 0
s' = -R/4
image is located a distance R/4 to the right of V.

Last edited: Sep 30, 2011