This wave demo is an easy to build and fun contraption. The materials are very easy to find and assemble and I would recommend building this for an project or demonstration if you have the time. It works very well and does not take a ridiculous amount of time to build.
Step 1: Assemble All Your Materials
You are going to want to get all of your materials ready before you start constructing this wave demo. I have created a good starting list that you can branch off of if you want to add anything that I do not use. The four most important materials that you will need are: Duct tape, kabob sticks, small weights to be stuck to the end of the kabob sticks, and two big bases to hold it up. For my small weights I have decided to use sour patch kids: watermelon. I felt that they were very easy to attach to the end of the kabob sticks and a good size to display this demo. For the two bases I used big jars.
Step 2: Attach All the Small Weights to the Kabob Sticks
Next you will want to stick all your small weights, my sour patch kids, to both ends of each kabob stick. I would say that a good number is around 20-30 kabob sticks so you will need 40-60 small weights. These sour patch kids will act as the particles of the wave moving up and down. It is very important to keep in mind that they weights should be placed evenly on both sides so our wave does not tilt to one side very heavily.
Step 3: Place the Kabob Sticks Onto the Tape
Once you have finished putting them onto the kabob sticks you will want to cut a piece of duct tape 2-4 feet long. Then you will begin placing the kabob sticks onto the tape one by one. You should make sure that you evenly space all the kabob sticks out so your wave will run as smoothly as possible. If you unevenly space the kabob sticks out it could ruin the wave and it is not very fun to have to take all the kabob sticks off of the tape and this will make the whole process much much longer.
Step 4: Placing the Next Piece of Tape On
After you have placed all your kabob sticks on the duct tape you will want to secure all of them by placing another piece of duct tape on top of all of them. You will want to cut another piece of tape the exact same length as the first one and place it exactly over the first piece of tape. It could end badly if you misplace the second piece of tape because when tape sticks to tape is very strong and not very easy to rip off. Also with your kabob sticks in the middle it could ruin them and you would have to start from the beginning again.
Step 5: Attaching It to the Bases
Once you have finished securing all the kabob sticks into the middle of the two pieces of tape it is time to attach all of that to the two bases. I recommend doing one very long piece of tape that attaches form the end of one base all the way across the other two to the end of the second base. Using only one piece of tape will make it much more unlikely to fall off and stay attached to the base. Also it is very important to put the long piece exactly of the two shorter pieces because you want it stay attached everywhere or it could ruin the wave. As you can see in the photo I decided to fill my jars (bases) with rice so they are heavier and much harder to slide closer to each other when you create tension in the tape to create the wave.
Step 6: Wave Property
This demo shows that given a certain tension and medium the wave speed will not change. The wave speed is constant unless you change the tension of the duct tape. You can test this by flicking the end and seeing the wave travel down the tape, and then flick the end much hard and you will see that it does no change how fast the wave travels form one end to the other. The only thing that will change if you flick it harder is amplitude.
Step 7: Problems
There were two problems that I encountered. One was that the candy I used was perishable and would not last. What I did to prevent this was I sprayed all of the sour patch kids with hairspray which should make them last longer. Also you could substitute the sour patch kids for different, non-perishable, small weight, for example clay. The other problem I encountered was the jars moving closer to each other. I prevented this by adding rice to both of the jars and making them heavier and harder to move. Another wave you could prevent this is to put a stopper in front of each base, such as pieces of wood.