Creating a Strong Straw Bridge: Tips and Guidelines for a Physics Class Project

[amwbonfire]

Hi everyone,

I've got to build a bridge from straws and pins for a year 12 physics class. Our bridges will be tested for strength by hanging weights off the bottom of them, and the strongest bridge wins. If the bridge collapses or the masses touch the ground, we fail.

Here's some more info:
- The bridge must cover a 50cm gap
- If the bridge falls onto the ground, collapses completely or the masses touch the ground, we fail
- 50 drinking straws are to be used
- Unlimited amounts of pins (sewing pins, the small ones) are allowed to join the straws together.
- The masses must be hung from the bottom of the bridge
- No central supports are allowed (we cannot have straw pillars holding up the bridge)

Any ideas for the strongest design?

Thanks!

 

[HallsofIvy]

Use lots and lots of triangles!

 

[amwbonfire]

Nifty!

Triangles are nifty!

Unfortunately, 50 straws wasn't enough to do much... It broke.

But it was really funny! (Well I thought so...)

 

[Alkatran]

You should've used a lot of triangles in an arc. That way the weight would be transferred onto the ends of the bridge instead of the center. The trick is finding that perfect arc...