We started a new chapter on mirrors this week in my ninth grade physics class. I was really happy with the lesson I planned and carried out today.
We have a waterfall schedule where once every seven days we have a longer class period of 70 minutes instead of 40. When the long period falls at the very beginning of a chapter it's a great opportunity for finding out exactly what the students already know, what misconceptions they may have, and jump right into an inquiry activity for some hands on discovery.
I introduced today's lesson by asking students what they know about mirrors. They have a whole lifetime's worth of experience using them, we should have a lot to say! They found it a little tough for each table's scribe to make a list of what they already knew about mirrors.
After that, one student remarked that it was hard because they knew so little. I prodded a bit to ask how do you know it's only a little? They led right off with all the things they want to know, or thought they should know about mirrors. And so we filled the second column.
After that the students performed two short activities on their own using plane mirrors and objects, and one group at a time would come up to my demonstration table to investigate the Pepper's Ghost illusion. Placing the unlit candle where the flame appeared to be was really helpful for illustrating where a mirror image appears to be in relation to the original object.
Finally, we made our third list of what we learned. Here is our document!
As a side note, I was really lucky that I decided to try out google docs today. My wireless keyboard died, so I connected my laptop to the wireless projector and started my document. Then that connection failed, so I went back to the CPU that normally connects to the projector, used the mouse to open google docs, and continued right on typing on my laptop!