# Bridges



## ninjaman123 (Oct 19, 2011)

So I have to build a bridge out of balsa wood that weighs less than 100 grams and supports over 100 pounds. Can someone give me a google sketchup model in inches or something similar? Oh it has to be at least 40cm long and 5cm wide and 5cm below it and the ground.


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## katonca (Aug 10, 2004)

I'd go this route. Those pigs have to weigh 100 lbs


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## cwwozniak (Nov 29, 2005)

Maybe the pictures on this site will give you some ideas ...

http://www.balsabridge.com/


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## jiml8 (Jul 3, 2005)

So you are doing science olympiad? I always enjoyed the bridge building competition. My team often won that competition - even at the state level - by using a combination arch/truss bridge. The secret is to laminate the arches, and build them on a form so that the arch is perfect; any imperfections vastly reduce the strength.

If you aren't up to that, just go with a truss bridge. Remember; triangles are strong and don't yield easily.

Oh, and by the way. If you really want to be competitive, you have to keep the bridge to about 25 grams or less.


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## daniel_b2380 (Jan 31, 2003)

ahh, i see somebody got their homework done for them


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## ninjaman123 (Oct 19, 2011)

Thank you all


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