Hi, we're building a popsicle stick bridge in physics and the criteria is that it must support 70kg (160 lbs) and rest over a gap of 55cm. The bridge must weigh 210g or less, or else marks will be deducted. We decided to go with triangles in our basic structure, but our problem at the moment is that the bridge keeps tilting one way when any weight is added. How can we prevent this from happening?

Question

anonymous · Answer

Triangles good choice. More cross struts needed?

anonymous · Answer

@electrokid hi, someone suggested that you may be able to help.

anonymous · Answer

If you can, it would be greatly appreciated.

anonymous · Answer

Is the bridge breaking up or just tilting over? If tilting, you could add sets of  "outriggers"  (see also "flying buttresses"] at both ends, using your triangle geometry. If breaking up, need to locate sites and double up on support there.

anonymous · Answer

It's tilting over. :/ Our bridge design looks similar to this: http://wesee.wikispaces.com/file/view/bridge3_screen.JPG/142874117/807x410/bridge3_screen.JPG

anonymous · Answer

You need to make it effectively wider. Can you put "shoes on it at both ends?
At one end, for example, put two sticks flat on the ground, perpendicular to the length of the bridge, each sticking out half a stick length to the side and meeting in the middle, a two-stick cross piece:    |====|

In practice, guy wires running from the bridge supports to pegs on either side might be used, but this may be out of the rules of the contest.

anonymous · Answer

We will try that, thank you!

anonymous · Answer

You are very welcome. Good luck!