How Far is the Final Image from the Object in a Two-Lens System?

[fball558]

Homework Statement

An object is 1.75 m to the left of a lens of focal length 0.62 m. A second lens of focal length -2.7 m is 0.52 m to the right of the first lens. Find the distance between the object and the final image formed by the second lens.

Homework Equations

(1/x1)+(1/image)= (1/focal point 1)

(1/x2 - image) + (1/x3)= (1/focal point 2)

The Attempt at a Solution

i use
x1=1.85
focal 1 = .62
solve for image in first equation

then use

x2=.52
focal 2 = -2.7
use the second equation and solve for x3
and get .526 m
i think I am following the steps right, but keep getting the wrong answer. any help would be great
thanks!

 

[rl.bhat]

In the problem xq1 is 1.75.
What is image distance?

 

[kerimek]

Your approach to solving this problem is correct. However, it is important to note that when dealing with lenses, the sign convention for focal length is different. A positive focal length indicates a convex lens, while a negative focal length indicates a concave lens. In this problem, the second lens has a focal length of -2.7 m, indicating that it is a concave lens. This means that the image formed by this lens will be virtual and located on the same side as the object. Therefore, the distance between the object and the final image will be the sum of the distances between the object and the first lens, and between the first lens and the second lens. In this case, the distance will be (1.85 + 0.52) m = 2.37 m. This is because the virtual image formed by the second lens will appear to be 0.52 m to the right of the first lens, which is already 1.85 m to the left of the object. I hope this helps clarify the solution for you.