Energy is transported by waves. That’s an important concept to teach students, but it’s not always an easy one for them to understand. At the beginning of our unit on the electromagnetic spectrum, my class and I made wave models so they could all see and understand how waves work.
The kids loved this activity when we did it in class and, when I run into former students, some tell me they still have their wave models hanging from their ceilings more than 10 years after we made them!
- Popsicle Sticks
- Kite String
- Low Melt Glue Gun
- Ruler or Yard Stick
- Pen, Pencil, or Marker
Have students lay out at least 91 (more is better) popsicle sticks side by side on a flat surface. Use a yardstick to assure they are even.
Find the center of one stick and mark lines 5 cm on either side of the center. Do the same on a second stick then lay them on the outermost side of the line of sticks.
Unroll enough string to stretch across all sticks and leave an additional 0.5 meters on either side. Tape the string down to the table so it is stretched tight across all 91 sticks and lined up on the top mark of the two outermost sticks. Do the same with string for the bottom mark.
Starting with the outermost stick place a dab of glue on the top string attaching it to the stick it is on. Do the same with the bottom string. Repeat this with every other stick until you reach the last stick. Once completed, un-tape the two strings on one side of the sticks and lift.
It they were glued properly, every other stick should fall away leaving behind your wave machine.
- Have students pair up with one wave machine between them. With each student holding onto an end, have one student tap the end of one of the sticks closest to him/her. What happens to the other sticks? Describe their motion. What happens when you tap the stick harder?
- Have a third student tap a stick halfway down the wave. Describe what happens.
- Have the two students on either end of the wave tap a stick closest to each of them at the same time. Describe the motion.
- Hang the wave model from a hook on the ceiling. Add a light weight to the bottom end of the wave. Tap a stick along the wave and describe the motion.
If you’re interested in a commercial product, you can check out the wave modeling spring from Educational Innovations. This 6-foot spring stretches to over 30 feet and is perfect for modeling both transverse and compression waves.