Question

If a lens has a focal length of 5 cm and an image is projected from an object that is 8cm from the lens, what is the image distance?

Answer 1

image distance = 40/13=3.08 cm

Explanation:

The relation of the object distance, image distance, and the focal length of a lens.

1/f =1/v -1/u

v = distance of the image from the lens.

u = distance of the object from the lens.

f = the focal length of the lens.

therefore,

1/5= 1/v -1/8

1/5+1/8=1/v

(8+5)/40=1/v

13/40=1/v

v=40/13 cm

v=3.08 cm