Showing posts with label bridges. Show all posts
Showing posts with label bridges. Show all posts

Friday, March 25, 2011

Physics: Bridges

This week the kids built bridges out of straws. Given 20 straws and some tape, the kids were challenged to build a bridge spanning 25 cm that would hold the maximum weight.

Monday, March 7, 2011

Physics: Bridge Basics

This week the kids built bridges out of index cards. They could bend or cut the cards anyway they liked, but the bridges had to span 10 cm, with no more than 1 cm at either end resting on the supporting books (once again an incomplete set of 1985 Encyclopedia Britannica comes in handy).

We tested the bridges to see which ones could support the most weight. The simplest flat bridges could hold around 30 g, while bending the card into a fan-like structure could support more than a half a kilo. Pretty cool!

We concluded by discussing how bridges and other structures often feature triangles because of their ability to transmit forces of tension and compression.