For my physics class, I need to build a derby car. Are there any tips or things I should look out for?
206673
Most derby's require no glass (even in the dash), no flamible items like upholstry, a more secure fuel source than the original tank, a roll cage and a better seat belt.
140782
Get him this:\nA zero deck (they got nice graphics, and they dont crack easily)\nGrind King Trucks (great trucks, i've been using mine for years)\nSpitfire wheels (ride smoothly)\nBones REDS bearings (really fast, and pretty cheap)\nBlack magic grip (lasts long)\n\nIf you have any more questions, feel free to email me at:\nbartsboy89@yahoo.com
345026
That is a complicated assignment for a child of that age.  It sounds more like what my seventh grader would be doing.  Actually they just got done with an assignment for science where they had to make a model car which ran on balloon power.  It's not even a full credit?  Ridiculous, you should talk to the principal or vice principal about such a complicated assignment.  Plus doing it over a holiday -- where's the holiday fun in that?!  Definately take that up with someone in authority, perhaps being in the industry they will listen.
394016
go 4 d c motor ,,,, model of it is easy n interesting, eye catcher.... i made that last yr n got highest marks... :-)... it ll include both elec n magnetics..
387755
We did something like this in my physics lab with an Atwood machine.  It was a pully with weights hanging from it.  I can't exactly remember how it worked, but maybe this will inspire you.  We also did something with an air track and these two masses colliding and we'd see which one would go in which diretcion.  You need a nearly frictionless surface, like an air hockey table or ice slab.
449032
USE PRINCIPLE OF CONSERVATION OF linear MOMENTUM.\n\nearth gas lower KE because it has huge mass and huge inertia
428189
OK I'm cheating - I put this answer up a little while ago.\n\nA quick and dirty idea for a physics project would be one based on electromagnetism. Without knowing what grade you're targeting, a simple one that has a fair amount of pizzazz is to build a gauss rifle. Checkout http://sci-toys.com/scitoys/scitoys/magnets/gauss.html\n\nThe sci-toys site has some other pretty cool stuff that you might find useful as well.\n\nFor a more advanced example, you can make a small rail gun that applies similar principles but can have a much larger kick. Just do a search on "rail gun experiment".\n\nEnjoy!!
59150
Ok assuming you are part of the real world and race on the street where they dont have a tree, sorry race chick. There are several things you can do to improve launch i have had a 89 mustang gt and i didnt do alot to the engine at first it was all about suspension and other things to get me off the line faster the first thing i done was put in a trunk mount battery kit to help waight transfer then 40/60 drag shocks fron edlebrock and eiback 1" lowering springs in the rear also i ran a pair of Nitto drag Radials and 3.73:1 rear gears you can email me @ williamb606@yahoo for specifics
64889
Go with the heads definately. While widening the ports and displacement would give you some gains the heads go alot farther. While you're doing the heads throw in a solid custom cam with hydrolic lifters and forged rods. Not only will you get bigger bang for the buck but it'll give you better runs at the track or on the street.
10626
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208399
Personally I would use 2 metal rods and a ball bearing or marble.  bend rods so they are spaced the same with loops first and then hills.  then find a way to project marble or ? with enough force to stay on track without falling off. try different speeds and re bending rods until satisfactory results are obtained.\n\nThat would be much easier than trying to do all the math required, then obtaining the speeds and angles required to build an actual roller coaster.\nThis should be acceptable for classroom project.
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http://www.scitoys.com/scitoys/scitoys/magnets/gauss.html\n\nAll the details, tips, and materials you will need. I had great fun experimenting with my first one, making it longer, adding more magnets, larger magnets and bearings etc. I managed to get hold of some great magnets and bearings the same size as a pool ball. \n\nI won't go into detail about what happened to my bedroom wall with that one though, it's another story.\n\nHope you like the site and have fun.\n\nPete.
257042
Depends on what kind of track you intend to use it on; straight, incline, etc. I doubt that aerodynamics will make a whole lot of difference, but you can try something aerodynamic. I've seen a number of pinewood derbies and I can't say the wedge always has the advantage. If it really made a difference nearly all would tend to win, but they don't. I tend to believe that other factors are more significant. Things like weight and friction. Make the wheels as 'slippery' as possible about the axles. Maybe you can use Teflon bushings for axle sleeves, or Teflon axles  as well as Teflon bushings unless there are restrictions of such things.\n\nAt one time I started to crunch some math to find the optimum design, but I was always derailed on some other endeavor and never finished. It's not a trivial problem actually if I remember correctly. Anyway, I'd say that the weight should be evenly distributed. So balance any added weight with the weight distribution of your body style so the mass is effectively centered width-wise and length-wise.\n\nA light car will leave the gate faster, but the heavier car will not be as affected by undulations and so on on the track, and it will tend to want to continue longer than the light car. How much heavier?........sorry.....dunno. That was part of what I wanted to find out.\n\nIf the cars start on an incline then I'd say the weight distribution should be slightly forward. If the cars are propelled on a level track, depending on the nature of the launching mechanism on the car the weight should be centered as I mentioned above. If the cars are propelled on a straight track from behind, then you'd also want a bit of excess weight slightly forward. If the car is propelled by a sling mounted on the front of the car, then the weight should be situated slightly toward the rear.\n\nThe wheels should have NO slop in them, but completely FREE to turn. The mounting of the axles should also be done just so as well. I'd say this is more in line with how you distribute the weight of the car as a whole. You don't want weight 'hanging' over beyond the outer perimeter of the wheel-base. And don't have it shifted more to one side than another. I doubt you'd do that, but I've seen some pretty crazy designs.\n\nSince you mention motors, I guess you'll be launching from a level surface. Make cavities in the car to lower the motor into to keep it from being too bulky. Selecting the motor is up to you. Find one that has a good power:weight ratio. Meaning.....high power against low weight (that's obvious ---- right?). Power it with good batteries. Don't get the cheap crap from Giant Eagle. Go to a hobby store and get good ones. Measure their voltage and make sure they are at or above their rating, and if you use more than one that they are as closely matched as you can get. Mount the motor as closely to the driven axle as possible. Avoid linkages. This will add weight...unless you have to. maybe consider driving all 4 wheels at once? BUT...they will have to be synced VERY well to pull this off, otherwise the car will fight itself and slow you down. If you need to do any wiring....use very fine gauge wire. Enough to handle the amps needed, but just barely! The finer the wire the less weight you have to haul. Ideally try and engineer the motor so you don't even need wires.\n\nIf you have to connect the motor to the axle with some kind of gearing....I'll come over and bi+ch-slap you for even thinking it......don't do that! Try and use a motor/axle assembly. Otherwise you run a terribly high risk of driving the axle out-of-center and wasting power by unnecessarily torqueing the axle. Meaning as well as turning the axle it will tend to want to rotate....no no no no no....got it?\n\nMake sure any motor you use doesn't have a wild magnetic field. Check it by seeing how many paper clips you can 'stick' to it, and how far away this
517247
Don't waste your money.Buy a car with a V8,and build that one.You can pick up an old 5.0 Mustang or a V8 Camaro from the mid to late 80's pretty cheap.Go get a HOT ROD MAGAZINE,you'll get plenty of ideas from it.
301187
GOOD IDEA.\n\nEven better - why not build more of the Japanese train (there's a small one in the UK too) which travels on the +/- polarity of magnets along with an accelerator.\nThere is no friction at all with these, and, apparently, no limit to a top speed !\n\nThere are no environmental issues either.\n\nBig question though, would the oil/gas companies allow it, seeing it would destroy their business ?
178779
Calculate the total energy of the system before and after and make an energy balance.\n\nFor example, lets say you have an inelastic collision between two cars of equal mass m:\n\nInitial State:\nCar 1 moves at v1 to the right\nCar 2 moves at v2 to the left\n\nAssume v1 > v2\nThey hit and stick together completely.  Use conservation of momentum to find the total resultant velocity:\n\np1 + p2 = ptotal (p is the momentum of car 1 and car 2 respectively)\n\nm*v1 - m*v2 = (m+m)*vf\n\nvf is the final velocity of the clump\nthe minus sign is because I am choosing the direction "right" as positive (momentum is a vector)\n\nvf = (v1-v2)/2\n\nNow do an energy balance:\n\nEbeforecollision = 1/2*m*(v1^2) + 1/2*m*(v2)^2\nEaftercollision = 1/2*(m+m)*(vf)^2 + Efrictionlosses\n\nEbefore = Eafter (this is conservation of energy, and it is true as long as you account for all forms of energy...it wont be true if you forget about the frictional losses in Eafter)\n\nNow solve for Efrictionlosses\n\nTo get the total fractional energy loss, take the ratio Efrictionlosses/Ebefore
631970
3 easy steps:\n - Build a car.\n - Power it with a rubber band.\n - Wind it up and let it run.\n\n\nGood Luck!