Exploring Light Reflectivity

Before beginning exploring light reflectivity we reviewed the powerful ideas that we have formed thus far.

We started off our exploration of light reflectivity with a mirror reflectivity activity. Have two students stand on opposite sides of a table, and the rest of the class surround the rest of the table. With the lights off, place a mirror in the center of the table and have one of the students on the end of the table point the flashlight towards the mirror. The flash light travels to the mirror and reflects into the student's face who is standing on the other side of the table. Two other students held meter sticks in the direction that the light was traveling from the flashlight to the mirror and the mirror to the student's face. We discussed the angle of incidence and angle of reflection and how they form the same angle. We also held the flashlight facing the table and found that the light reflected in all directions because it is a rough surface.

Each group is given a light sensor to explore light and the new equipment.

After the initial exploration ask how you make a graph look like…

• a W?
• a sharp W?
• a rounded W?
• a M?
• a sharp M?
• a rounded M?

Have students trace the graph with their finger and tell the story of making each letter. Ask how they would tell the story of making a line that rises steeply/descends steeply.

Students intial exploration with the light sensor and folder of different colored/textured materials.

Students are given a folder containing different materials and asked to explore with the light sensor and how the graph changes. Each group came up with a question, a way of recording and finding an answer to their question.

• Group 1

How does color/material affect how much reflecting light is measured? - Foil is the most reflective - The dark cloth was less reflective than the white cloth

• Group 2

Will the difference in colored paper make a dfference in how much light is reflected? - there was a big difference in the white and black - the color did make a difference in reflectivity

• Group 3

Which paper type is most reflective? Does color matter? - the foil was most reflective compared to the other materials - the black paper had no reflectivity