Spaguetti Bridge

Today we had another great day trying the experiments suggested on the "Time for Kids - Big Book of What, How and Why?". My son wanted to build a spaghetti bridge, he was quite excited to make the bridge but it was difficult to make him not eat the spaghetti and marshmallows :)))).

The materials you need to build the bridge are:
*8 marshmallows;
*2-3 uncooked linguini;
*13-14 strand of uncooked spaghetti (try to use spaghetti that's about the same diameter as the linguini);
*1 paper clip;
*1 envelope;
*scissors;
*40 coins (we used only pennies as we would obtain the same weight in all the experiments).

 

Instrucitons:

1st step: Use the scissors to snip off one corner of the envelope. This will be a coin basket. Afterwards, unbend one end of the paper clip. Poke it through the top of the envelope and bend it into a hook shape so it holds the coin basket.

2nd step: Make two pyramids of equal size by sticking the spaghetti through the marshmallows. Each pyramid will need four marshmallows  and six strands of spaghetti.

3rd step: Stand up the two pyramids near each other so they are less than the length of a spaghetti strand apart. Then, connect one end of a strand of spaghetti to the marshmallow at the top of one pyramid. Connect the other end to the marshmallow atop the other pyramid.

4th step: Hang the coin basket in the middle of the strand of spaghetti that connects the two pyramids. This is the bridge.

5th step:  Add coins one by one to the basket until the spaghetti breaks. Note how many coins it takes to break the bridge. My son put 18 pennies on the envelope.

6th step: Connect the two pyramids with a strand of linguini. Repeat the experiment. Note the difference in the number of coins it took to make each bridge collapse. My son put 38 pennies this time.

Afterwards I asked a few questions to my son to make him understand the difference between the two materials:
*What is the shape of the linguini?
*What is the shape of the spaghetti?
*Do they have the same texture?
*Which one is thicker or thinner?
*Why do you think the linguini held more coins than the spaghetti?

 Based on the book the spaghetti is supposed to hold more coins than the linguini because "the spaghetti pyramids are made of triangles. Triangles are strong  because they are rigid and won't bend. Spaghetti is shaped like a cylinder, and round objects have great strength. Stress is distributed equally throughout them, and they will bend in any direction. The linguini is shaped like a rectangle and so it bends and breaks."

Taking everything above into account, we figured that the problem we had was our linguini was thicker than the spaghetti hence not measuring like for like. The linguini held 38 pennies and the spaghetti 18 pennies. Next time we create this bridge we will make sure to have the same diameter for the linguini and spaghetti.

 My son had the idea to have two strands of spaghetti to hold the basket of coins. It held 28 pennies until it collapsed.

It was a fun, very interesting and delicious project. My son enjoyed it very much, he ate almost everything :))).
Have a great weekend. Thanks :)))!!!!!

Fabiana