Boom Box Tube Challenge to Excellence 2009 Science Fair Project

Big Question How do sound waves move through a boom box tube? Can they make foam beads move through vibrations?

Explanation of Big Question If sound travels through vibrations then it should make the foam beads move inside the boom box tube because the tube should move with the vibrations making the foam beads move. We should be able to see the foam beads when the sound moves through the boom box and vibrates off the boom box tube.

Hypothesis If sound travels through the air in waves, then by using plastic foam beads we should be able to see sound waves when they move through vibrations in the boom box tube. Explanation: I believe my hypothesis will work because I will be building a boom box tube and conducting the experiment. My research will also support my hypothesis. See next slide for picture of foam beads used in tube.

Research Research shows that my experiment works like our ears and hearing. When sound waves enter the ear canal, the waves strike the eardrum and makes it vibrate back and forth. The incus bone starts to vibrate and the stapes. This pushes on the cochlea which sends signals to the brain and the brain says they are sounds. This is what the boom box did to the beads. The sound waves ran through the boom box and sent a vibrating signal into the tube which made the beads move. This was a sound wave. See next slide for picture.

Research Sound is described in many ways. It can be noisy, musical, loud or soft. People put sounds in groups so they can understand how they are heard. Like when a loud train comes by and you are standing close and may want to cover your ears or when you are at a concert and there is softer music being played so you enjoy it.

Research If you are in your bedroom you can hear sound from other areas in the house. How does sound travel through walls? Sound can travel through solids, liquids and gases. Sound not only travels through air, but also through wood and glass and any other material that vibrates. These materials are made up of air particles that mix with the sound while it is traveling. Sound travels at about 1,087 feet per second.

Research Sound waves are sound vibrations that move in curved up and down patterns. The size and speed of the sound determines what kind of sound is made. The bigger the vibration the taller the sound wave. Loud sounds can be heard from far away because sound waves travel with energy. As the sound spreads out the vibration gets smaller.

Experiment – Materials Needed 4 foot 2 inch long plexiglass tube 4 inch diameter opening 7X6 flat plexiglass piece Plexiglass glue Measuring cup 4 cups of plastic foam beads 2 pieces of plywood - 6X9 inches each 2 angled pieces of wood to support tube on its side creating a V shape on top of the plywood. Boom box with microphone Research books on sound

Experiment – Building the tube Step by Step Instructions Using a 4 foot 2 inch plexiglass tube, I glued a 7X6 flat plexiglass piece on one side closing the tube on one end. I built two support wood structures using 2- 6X9 inch pieces of plywood and glued 2 angled wood pieces to the 6X9 pieces of plywood to make a V shaped support for the tube. I poured 4 cups of plastic foam beads into the plexiglass tube and put the tube on the end that is closed. The beads were moved around the tube so they would spread out more evenly. I placed the plexiglass tube on its side horizontally on the 2 support V-shaped wood structures. Then I put the open end of the plexiglass tube next to the speaker of the boom box. See next slide for picture.

Instructions to Complete Experiment Using different noises, sounds, and music with a boom box and microphone, I will prove that sound waves move through a boom box tube and vibrate making the foam beads move. Each of these tests should make the foam beads move to the sound vibrations. I will also change the volume to see if this makes a difference in how the foam beads move. I will collect data and observe each thing I try.

Control/Variable The control group was the foam beads because they remained in the tube. The variable was the boom box because I made different sounds and the volume was changed and the placement of the microphone was moved.

Running the Experiment - #1 Observations Several experiments were done to test my hypothesis. First experiment: I turned on the boom box and placed music on to see if that would make the foam beads move from the vibrations of sound against the tube. I also changed to volume to see if that would make a difference. This did not work as well as I thought it would. The sound did not reach all of the beads inside the tube. See next slide for picture.

Running the Experiment - #2 Observations The next time I used a microphone and altered the sound by using different kinds of sounds like; tapping, drums, symbols, whistling. The beads moved more than just with music. See next slide for picture.

Running the Experiment - #3 Observations Then I yelled into the microphone. This made the most beads move. The loudness of my voice seemed to work the best to make the beads move. See next slide for picture.

Running the Experiment - #4 Observations I decided to try one more thing and put the microphone near the speaker causing a very high pitched sound louder than anything I had tried. This made the beads move around the most and made the experiment more successful. See next slide for picture.

Data Data is included in the experiment and observation slides.

Analysis of Data My hypothesis says that the beads would move due to the vibration of sound waves. And that we would see the sound waves working when the beads moved. Even though certain sound waves made the beads move more or less, it did test and prove my hypothesis to be true. The pictures of the beads in movement show that my experiment was successful.

Conclusion My hypothesis was correct. The foam beads did move to sound waves through the vibration in the plexiglass tube. I would make the tube smaller in size if I were to use a similar boom box to do the experiment again to test if all the beads further in the tube would move to sound waves. I would also try a stronger boom box and see if the same sounds I made in this experiment would change the outcome of the amount of foam beads that moved.

References – picture images Gray,S.(2006) The Ears. Parker,S.(2005) The Science of Sound. Spilsbury,R. and L.(2008)What is Sound? Walker,R.(2009) Eyewitness Human Body. Wright,L.(2000)The Science of Noise.

End Credits Thank you for watching. Boom Box Tube produced by Brian Morgans. See ya later Bye