Lens maker equation:

$\overline{)\frac{\mathbf{1}}{{\mathit{s}}_{\mathit{o}}}{\mathbf{+}}\frac{\mathbf{1}}{{\mathit{s}}_{\mathit{i}}}{\mathbf{=}}\frac{\mathbf{1}}{\mathit{f}}}$

Power of a lens:

$\overline{){\mathbf{D}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{f}}}$

For the combined lens:

Oscar has an old-fashioned lantern projector that uses a candle and a lens to project a slide onto the wall. The lens is 1.2 cm from the slide and projects an image onto a screen 80 cm away. Oscar adds a lens to the original lens to allow him to project an image onto a screen 30 cm away.

What is the desired power of the combined lenses?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Thin Lens And Lens Maker Equations concept. You can view video lessons to learn Thin Lens And Lens Maker Equations. Or if you need more Thin Lens And Lens Maker Equations practice, you can also practice Thin Lens And Lens Maker Equations practice problems.