Incident, Reflection, Refraction Laser Demo
Summary:
In this lesson, students engaged with a demonstration using a vase and a laser to learn about incident, reflected, and refracted rays. Students then predicted, explained, and identified where they would see reflected and refracted rays knowing where the incident ray would be.
Background:
I created this demonstration after my students had attempted on MCAS Open Response problem on incident, reflected, and refracted rays. They were given the picture below (image on left side) and asked to try and identify the three as an incident, a refracted, or a reflected ray.
My mentor teacher and I had yet to cover the material, but wanted the students to see that with their own sense making, they had the ability to figure out parts of the problem (which one is the reflected ray) and to make an educated guesses on other parts. I realized though from having certain students talk through the problem with me and from reading other students responses that students were having a difficult time with what the arrows were representing. Although they knew what reflections are, they had not seen it represented this way before. Even after being given the definitions of incident, a refracted, or a reflected ray, students were still having a difficult time.
In response to my students, I started thinking about ways to bring the concept more to life in a way that they could actually see and interact with the incident, refracted, and reflected rays. That weekend, I found a rectangular vase from a garage sale. I discovered that by having a filled vase with water that had a little four mixed in and spraying a fine mist of water around the vase, I could shine a laser and see the incident, reflected and refracted rays.
The demonstration helped generate intrigue among the students and made the topic tangible. From it, students could identify and describe each ray. Additionally, they could predict where the three rays would be if the laser moved and could experiment to prove it!
Click Here to go back to Sample Lessons.
In response to my students, I started thinking about ways to bring the concept more to life in a way that they could actually see and interact with the incident, refracted, and reflected rays. That weekend, I found a rectangular vase from a garage sale. I discovered that by having a filled vase with water that had a little four mixed in and spraying a fine mist of water around the vase, I could shine a laser and see the incident, reflected and refracted rays.
The demonstration helped generate intrigue among the students and made the topic tangible. From it, students could identify and describe each ray. Additionally, they could predict where the three rays would be if the laser moved and could experiment to prove it!
Click Here to go back to Sample Lessons.