These should play full screen if you expand the window. You may be able to access them on YouTube directly, but sometimes that doesn't work at school.
Light and Shadows (Genova, 5:41)
Determining the length of a shadow on a screen, or doing similar calculations.
Light and Shadows, Advanced (Genova, 8:44)
Shadow problems that require a little more work. Honors level.
Can They See Each Other? (Genova, 2:56)
When given the placement of two people and a flat mirror, determine if they can see each other.
Where Should the Mirror Go? (Genova, 3:20)
Given two people's locations in a room, where would you place a flat mirror so they can see each other?
Refraction (Genova, 5:58)
How to determine if lights speeds up or slows down when it enters a new medium, and which direction will it bend.
Investigating an Unknown Medium (Genova, 3:55)
Using the Phet simulator to estimate the index of refraction of an unknown medium.