Scioly.org

It is the Physical Science Lab wiki for B not Physics Lab for C. But you may want to add that anyway and that you still can use only 1 if you want to.

It's the wiki for both. If you go to the wiki main page and click on Physical Science Lab under B it brings you to the same page as if you click on Physics Lab under C. There is also a separate Physics Lab wiki for the past subjects of Physics Lab.

They should still read the rules to know that. You can't just make blades without reading the rules first.

In the link it does say Physical Science Lab.

Hey, what voltages are people getting specifically in C division?

Even though I'm not from division C, experience has shown that just by saying a voltage is useless for comparison because the rotor the CD spins on could seriously affect the voltage... Our normal voltage was halved when we tried out out high school's rotor.

Just finished optimizing our design for nationals. I just wanna say that at a certain point, once you've taken off all the excess mass you can, mass isn't really a factor anymore. Especially as high speed, the bigger factor becomes aerodynamics, drag, and turbulence. It's a good idea (in my experience) to taper the leading and trailing edges of the blades to decrease drag and turbulence. The entire surface area of the blades should be aerodynamically useful; don't leave the center flat. Also, stability is key. If it makes too much noise, it's probably unstable. Noise (vibration) is wasted energy. Also unless you have some wicked design that intentionally morphs with different wind speeds to make it better, which i have never seen but it would be amazing, bending is generally bad. Finally, don't make the same mistake we made last year at states. We got a score of 0 because our blades were just slightly touching the back of the setup. We ended up with 3rd overall, and our place in physics lab was bigger than the difference between us and nationals. Don't risk it. On the other hand at nationals there's nothing to loose!

Here are some results from C-division nationals if anyone is interested.

The test was very easy and so basically the best blades won. The way they had it set up was that there was a high speed fan and a low speed fan. At each fan, they would record your reading for that speed. The fans were not particularly fast and neither were the motors. Of course, that doesn't matter since everyone had the same setup.

Our readings were (these could be slightly off) 1628mV on high and 1287mV on low. We were the very last team to test and were told that our blades were 2nd but very close to Troy's on high power and the fastest in the nation on low power. We took 2nd overall. We got the impression that the 3rd place team was significantly slower but perhaps we were mistaken.

I would also like to say that we got the results we did without any outside design help and so definitely anyone who was motivated enough could have done as well as we did. I molded basswood blades on a metal pipe to get the right curvature. My approach was highly experimental: I changed one variable at a time until I basically got what seemed to be a near-optimal design. Once I had a really good design, I molded several blades to get 2 that were close to identical. In all, I probably molded about 40 pairs of blades to find the design I used and about 10 to get 2 blades that were identical. I learned a huge amount along the way just by observing what worked and by thinking about the physics that determine how the blades function.

Division B Physical Science Lab

Our high speed voltage was 2160mV and our low speed voltage was 1166mV. How were some of the other scores for the fan voltages in Division B?

--We got Third in the Nation!!!--

can you put pics on the image gallery for others to see. thanks and have a nice day

Great job guys!!! In division B, we got 8th, with a high of about 1830 and a low of about 900. We were the fastest in PA (by a lot; we know the guys at Strath Haven who got 2nd place), so we didn't change our design much since then. The test was kind of easy, but there were some weird parts, like that thing about that energy bill. I may eventually post pictures or specifics about my design, but I'll have to talk to some people first. Also, it seems that there were 7 designs out there that would be more helpful than mine! Congratulations guys!!!