Welcome!

This is a blog of the 4th grade class in la Farigola de Vallcarca School in Barcelona. This year we are doing “Aula de Ciències” in English.
In this blog we want to show you the experiments we do in our Science Lab. Science is fun!


dimecres, 17 de novembre de 2010

Building bridges

MATERIALS:
4 thick books
1 piece of cardboard
paper clips
rubbers
INSTRUCTIONS:
Put the books in two piles about 15 cm apart.
Lay the piece of the cardboard on the books.
Put paper clips on the cardboard. Count them. The "bridge" starts to sag. Finally the bridge collapses.
Now make another bridge, but bend the piece of cardboard into an arch between the books.
Put paper clips and rubbers until it collapses.
This bridge is stronger than the first one.
WHY?
The first bridge collapses before because it is flat and it has to take all the weight.
In the second bridge the weight goes to the sides and it is shared by the books, so the card can support more weight.
WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS.