Science Buddies: "Ask an Expert"

I am doing the "Wily Waves" project on Science Buddies, and I am confused about the construction. How do I attach the rubber gasket or rubber packing material to the hub cab to seal it? I have a sheet of rubber gasket that is 6" wide and 6" long. It is 1/16 " thick, and I need to cut it down the size of the hub (4" diameter) and attach it so that air does not escape through the sides. How would I do that?

Thanks,

Hi claram1,

Try using scissors to cut holes in the rubber gasket that match the holes you cut in the cap hub. Align the two sets of holes so that they match up. The seal is created when the gasket is compressed or squeezed between the fan and the cap hub as you tighten the four fan screws. The gasket is held in place by pressure.

Let us know how it goes!

Thank you. I have another question. I attempted to complete the project with a PVC pipe, but my readings fluctuated between 0 and .1 for only the highest waves. I noticed that the PVC pipe was very heavy. Is the ABS pipe (that is recommended in the project) be lighter than the PVC pipe? Would the pipe weight affect the voltage?

Hi claram1,

Unfortunately I am not familiar with the typical data set that comes out of this experiment, but it is an excellent idea to examine any procedure differences if you suspect they might have affected your results. I do want to point out, however, the note in the “Analyzing Your Data” section of the experiment that states:

“Note: Keep in mind that your current measurements will not be in the full ampere range, but more likely in the milliampere range and you will have to account for this in your plot.”

If that doesn’t help, I found this website comparing PVC and ABS pipe:

http://www.diffen.com/difference/ABS_vs_PVC

One thing I noticed is that there is a difference in flexibility between the two materials. ABS pipe is significantly more rigid at cooler temperatures. How do you think this might have affected your device’s interaction with the waves during the procedure? Are there any other differences for the PVC that might have had an effect?

Thank you dfcoll. Your comments were very helpful!