# Resolution of Optical Instruments Question

smoics

## Homework Statement

A 3.1 cm--tall object is 26 cm to the left of a lens with a focal length of 13 cm. A second lens with a focal length of 8.0 cm is 42 cm to the right of the first lens.

## Homework Equations

1/s + 1/s' =1/f
M=-s'/s and I'll have to multiply the two M's together to get the final M.

## The Attempt at a Solution

I drew out a ray diagram. Maybe my signs are wrong?? 1/-26 + 1/s' = 1/13. s'=-8.67. This would be to the left of the first lens, so I tried doing 42+ s' and also 42-s' to use in the thin lens equation the second time (As the distance from lens 2), but none of my answers are working...?

## Answers and Replies

smoics
Calculate the distance between image and the second lens.
and Calculate the image height.