Question

This object is located 6.0 cm to the left of the lens, and the image forms at 28.7 cm to the right of the lens.What is the focal length of the lens?

Answer 1

Let's use the common formula:

1/f = 1/i + 1/o, where

f: focal length, i: image distance, o: object distance

1/f = 1/28.7 + 1/6

1/f = 0.2015

f = 4.9625 cm