Phase Two of Reflected Light

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Objective

Students will be able to apply knowledge of the line of reflection.

Big Idea

Following a lot of fun work with reflection, students will prove their knowledge and create complex mazes for light to travel.

Question

5 minutes

Our question today will be, "What did you learn yesterday that can help you hit a target that is not directly across from a light source?"

Mini Lesson

10 minutes

My mini lesson will be very short today, as the activity will be a continuation of yesterday.  I will simply remind them that their flashlight (source) must remain in the same place so that it will not be a changing variable. 

I will also review some of what I saw yesterday, which was successful reflections from one and two mirrors. I will ask a few groups to model their obstacle courses and I will also have the children discuss what they want to try with their teams before leaving for their work space. 

The task will be to navigate their light ray to a target that is set to the side of the source.  The only variables they should change are the number of mirrors and the angle of mirrors. 

The students will begin with one mirror.  When that is successful, they will then add in a second, and then a third, and so on until they can use all 5 mirrors. 

Active Engagement

20 minutes

Before each group began, they were prompted to draw out their plan first. Then they could build their idea and revise the drawing if the plan needed changes. This is a powerful strategy to help the students question, plan an investigation, and then revise based on results. 

As the students work, I will again circulate and listen in. I will be watching and listening for several things during this time. This group is working with each other to make sense of the line of reflection. Turn your sound up for this…they were pretty quiet!  The discussion is how can the light reflect off of all the mirrors (girl).  The boy in the group was explaining that the light reflects on an angle opposite the source.  They needed to take away the other mirrors for her to see this. 

As the kids were working, one group of boys came up and told me about a "game" they got over the holidays called Laser Maze, which reminded them of this activity.  Man-wish I had thought of this first and got it on the market! They were able to use their knowledge from the game to succeed in this activity.  I promptly ordered two sets for my classroom.

 

Closing

10 minutes

In order to close, I decided to do a bit of an "exit ticket" activity on the board.  I placed a drawing of a source and a target and asked students to come up and draw a schematic with mirrors and light to make a successful hit. 

Prior to this, I placed several reflection models on the board and asked students to defend whether they are correctly drawn or not. This student explains, without precise vocabulary, why this is correct. Notice that my source is not in the right place.  This was a source of debate in the class and I was glad they caught it!

These next two videos show students drawing their schematics.  Notice that this allows for a diverse entry point.  The first student does a clean, direct schematic, while the other student challenges himself to use several reflection lines. Both boys are successful.