Lenses

Today we are going to work with lenses.  Lenses can manipulate light in a similar fashion as mirrors.  One lens will cause light to spread out and another lens will cause light to come together at a focal point.  The notes we are going to work on today can be found here and the answer key can be found here.
The start up for today is "What kind of a lens causes light to come together at a focal point?"
Concave lens

Convex lens