How do I solve this thin lens equation? 1/d(o)+1/d(i)=1/f.

Question

Given a lens with a focal length of +0.10 m. If an object is placed 0.30 m from the lens, then how far from the lens will the image be formed?

A 0.60 m tall object is placed 0.20 m in front of a second lens, and the focused image is located 0.40 m from the lens, what us the height of the image?

Answer 1

f= 0.10 m   o=0.30 m     i=?

1/do + 1/di= 1/f

1/di= 1/f- 1/do

     =1/0.10m- 1/0.30m

     =10m- 3.3333m

1/di = 6.6667m

di=0.1499m

The distance from the lens to the real image is 0.1499m.

 

The next question is solved with the magnification equation.