April 18, 2008

By: Jeff G. from Philadelphia, PA
Comments: 6

Guys, I just found a website : www.expertvillage.com look at it for a bit and you will find so many How-To video lessons for many different disciplines. I think that you might find some of the experiments that you may like for the class. Design on! - Franc

Posted By: Jeff Gerstemeier
On: 2/2/2008 12:30:54 PM

I'm a physics teacher who is surrounded by design teachers. Much of what I do in class is very compatible with and informed by the design process (which is very similar to the scientific method after all). I'm interested in taking the hands-on projects that are part of my class, and making them more overtly design conscious. For example, several of my students volunteer at a local seaport museum in Philadelphia building racing sailboats. This connects to my class through the lessons I teach on buoyancy, torque, kinematics, etc... I am looking for a way to inject design into this group of concepts to tie them together so that all of my students gain an understanding of the physics involved, as well as how the design process is used. It would be easy if I could bring all my students to the museum and get them involved in the actual design and construction of the boats, but since space is an issue, I can't do that. I'm looking for ideas on how to incorporate design, construction, and physics into a balanced project that I could do with slightly limited resources and space, and 75 students.

Posted By: Don Domes
On: 2/11/2008 3:10:11 AM

Jeff, I am a tech teacher, but I have taught a lot for my Science department. When I can not build full size solutions I scale down to models. The bridge contest that our physics department conducted was a model contest. I loved to do water rockets using the soda pop bottles when I taught physical science. We shot them to the side for distance so we can get accurate measurements. There were so many variables and concepts (force, momentum, inertia, acceleration, compression of air vs. a liquid, angle of launch, etc.) We had a 20 oz. pop bottle go over 300 feet with about 80 psi of air. The kids loved that unit. I also did a lot of simple machines work with Lego's. You are correct that the scientific method is very similar to the design cycle. Tech teachers do tons of project based science in a design context. I suggest you look at tech suppliers like Pitsco for ideas. www.pitsco.com Don Domes, Hillsboro High School, Oregon

Posted By: Jeff Gerstemeier
On: 2/11/2008 2:32:10 PM

Thanks Don!! I was leaning towards some form of modeling project to do in conjunction with the boat building club at the seaport museum. Pitsco is a great idea as well!! I use them for CO2 car resources already, so I don't know why I didn't think of it myself!! regarding the soda bottle rocket project, I'm interested to know how much variation there was between rockets. Did you allow students to do things like add fins or control surfaces? Could they vary the amount of water? Did you use a bike pump or compressor to pressurize the bottles? What I'm trying to do is come up with more variables to inject into these projects so that students have a wider range of possibilities to consider when they're designing their solutions. I appreciate your input. Jeff

Posted By: Don Domes
On: 2/29/2008 3:10:28 AM

Jeff, I allowed almost anything on the pop bottles. The variations are endless, especially the amount of weight you add to the nose cone. We would talk about what might work better and then design an experiement to test our hypothesis. Then after running the experiements we talked about if we really did enough trials to get statistically valid results that were predictable. I used a portable compressor that Home Depot sells for about $40. It is rechargeable and is black. I set up a air hose line so we were about 20 feet away at the time we lauched. I built all the launching equipment and the air hose system. We had standard air compressor connectors so we could put as many lengths of air hose in the middle as we wanted. This got us well away from the launcher so we could even test high psi ideas (pop bottles will explode if you get too much compressed air in them). The hand pumps are problematic in that the reverse valve can be leaky, etc. I used a standard tire valve and put it in line with the system. I also set up a bleed off valve so I could always abort a pressureized launch. Because the pump was a battery powered portable thing we usually used the middle of the football field for our trials. Don Domes

Posted By: Jeff Gerstemeier
On: 3/3/2008 7:46:05 PM

Nice. Thanks for the info. I'm definitely heading out to Home Depot for a compressor. Any thoughts on Building and using a small wind tunnel? I want to be able to demonstrate the aerodynamics of various car shapes when my students design their CO2 dragsters. My plan so far is to play with a variety of fans from computer cpu fans up to small room fans till I get something that I can use. In the absence of any real vernier type sensors I think I'll set the whole thing up so that the car pushes on a thin wire mounted on a pivot that will lead to a digital balance so we can read the amount of drag in grams. Any ideas? Jeff Gerstemeier

Posted By: Don Domes
On: 4/16/2008 4:16:01 AM

Jeff, I have never done the wind tunnel projects so I don't know easy answers to that system. Interesting that you mention Vernier sensors. Dave Vernier used to be a Physics teacher in my high school!! He is still very active in our community and his business is just a few miles away. I highly recomend his stuff. https://www.vernier.com/ He has an awesome new adapter that interfaces many of his sensors to the new Lego NXT.

Posted By: Franc Leo
On: 4/18/2008 9:31:24 PM

Guys, I just found a website : www.expertvillage.com look at it for a bit and you will find so many How-To video lessons for many different disciplines. I think that you might find some of the experiments that you may like for the class. Design on! - Franc