Day 156 – Concave Mirrors




Physics 11 – Today we continued with our investigation into mirrors.  Students found the focal length of a mirror by projecting an image from a distant object.  Next they were asked to find the image distance for a given object distance, using three different methods: direct measurement, calculation using the focal length, and doing a scaled ray diagram.

As I noted from last day in physics, I hoped that students could use a cooperative learning environment to successfully solve mirror problems.  It turned out that the substitute felt that kids should work quietly and independently.  Uh huh.


Day 150 – Ray Diagrams and Plane Mirrors


Physics 11 – I had students try to project an image from a plane mirror on to a screen.  I can be cruel at times. This leads to a discrepant event – what is a real image and what is a virtual image? I don’t let them struggle for too long…