Lenses problems

IV. Application

6. If someone's face is 22 cm tall and is 100 cm from a convex lens that has a focal length of 20 cm, how tall is his image? Describe the image.

7. If the same face is now 15 cm from the same lens, how tall is the image? Describe it.

8. If the same face is 100 cm from a concave lens (in a peep hole of a door) that has a focal length of -20 cm, how large is the image? Describe it.

Go back to ray diagrams for help.
Go back to equations for help.
Index for Lenses.