Reflection Race: exploring reflection of light

Students will develop an understanding of angles of reflection as well as problem solving and team-work skills. Key concepts include; reflection of light in a fluid medium and angle of reflection from the original angle of incident. Key words include angle of reflection, reflection, angle of incident, light and laser.

This is an excellent introductory activity prior to lecture on the subject of optics. This can be done in the classroom or lab and requires only a laser pointer and several small mirrors. Time requirement is flexible depending on your class, additional challenges can be added as needed (i.e. have them reflect light from one room to another or even several rooms). This activity does work best in a darkened room, but does not require complete dark.

Divide students into small groups, in whatever manner works best for you, distribute 3-5 mirrors, and one laser pointer to each group. Introduce the activity by asking if they can use their mirror to reflect light onto the "board" Next they have 5 minutes to plan how to get a beam of laser light from the back of the room to the target. When time is up student groups will "race" to get their light to the target first. If they struggle too much you can decrease the number of mirrors. Prizes can be awarded if desired.

Always encourage proper safety with the laser pointers, especially not directing them at anyone's eyes. For more advanced classes, have them measure the angles of each mirror and calculate the angle of reflection. Different colored laser pointers can be used for each group, if available.

As this is an introductory or reinforcing activity no assessment is necessary or can be accomplished via an optics exam.

9P.2.3.3.4 properties of light