Wind Power B/C

[AlphaTauri]

One of these things (please don't tell me you've never seen one):

[samlan16]

Okay, another question on building this device. How are we supposed to attach our CD to the stand? On the rules, it says a CD motor hub, but what even is that?

You could salvage one from an old CD drive. That's what we did.

[EagleScout]

For the 2015-2016 competition, what level of voltage generation would be considered good?

[SPP SciO]

Trying to get a set-up ready so we can start testing - this came in the mail: http://www.amazon.com/RF-300FA-12350-5- ... B00880CKEI Unfortunately, it doesn't have those little spring clips that will hold the CD in place, so I don't think we'll get it to work. Old CD players are pretty common though, so I think we'll just salvage one from somewhere.

Also, can anyone shed some light on resistors? The rules specify 5-7.5 ohms. We got these: http://www.radioshack.com/1-8-watt-carb ... 10003.html , working under the assumption that we can wire a few together to get different resistances, etc.. But was the 1/8 watt the right choice? It seemed like the smallest available; would 1/4 watt resistors work also? Thanks!

[JonB]

Trying to get a set-up ready so we can start testing - this came in the mail: http://www.amazon.com/RF-300FA-12350-5- ... B00880CKEI Unfortunately, it doesn't have those little spring clips that will hold the CD in place, so I don't think we'll get it to work. Old CD players are pretty common though, so I think we'll just salvage one from somewhere.

Also, can anyone shed some light on resistors? The rules specify 5-7.5 ohms. We got these: http://www.radioshack.com/1-8-watt-carb ... 10003.html , working under the assumption that we can wire a few together to get different resistances, etc.. But was the 1/8 watt the right choice? It seemed like the smallest available; would 1/4 watt resistors work also? Thanks!

Old CD or DVD players are your best bet. It is surprising how commonly you can find an old on laying around. Someone on your team surely has an old player not used in the last 5 years they would be willing to sacrifice.

As for resistors- I will let someone else tackle that one.

[Daniel_Musheev]

What voltage are you guys getting out of your wind turbines?

[SPP SciO]

Also, can anyone shed some light on resistors? The rules specify 5-7.5 ohms. We got these: http://www.radioshack.com/1-8-watt-carb ... 10003.html , working under the assumption that we can wire a few together to get different resistances, etc.. But was the 1/8 watt the right choice? It seemed like the smallest available; would 1/4 watt resistors work also? Thanks!

http://scioly.org/phpBB3/viewtopic.php? ... 45#p129933 <-- In case anyone else had the same issue, this post pretty much nails it.

[Daquan]

Does anyone know what type of problems will be given as calculation problems? I am having trouble understanding what the would be like. Thank you for your help.

[samlan16]

Does anyone know what type of problems will be given as calculation problems? I am having trouble understanding what the would be like. Thank you for your help.

Expect conservation of energy, circuit problems (Ohm's Law), and work. An AP Physics review site may help.

[chalker]

Also, can anyone shed some light on resistors? The rules specify 5-7.5 ohms. We got these: http://www.radioshack.com/1-8-watt-carb ... 10003.html , working under the assumption that we can wire a few together to get different resistances, etc.. But was the 1/8 watt the right choice? It seemed like the smallest available; would 1/4 watt resistors work also? Thanks!

http://scioly.org/phpBB3/viewtopic.php? ... 45#p129933 <-- In case anyone else had the same issue, this post pretty much nails it.

That posts explains things pretty well, but makes a big assumption that isn't necessarily valid: that the output voltage is typically around 2V. If I recall correctly, I think the voltages are typically around 1/10th that, in the .2-.4V range. Thus, using P=IV=V*V/R= .3*.3/6 = 0.015 Watts. Standard 1/8W resistors should be more than sufficient for this event (as would anything bigger, such as 1/4W or 1/2W)