HELP - Science Fair Project!?

Question

My 5 year old son has got a ‘Science Fair’ day. He has been asked to make something which has at least TWO moving parts. I failed my CDT (Craft, Design and Technology) GCSE at school with style. I need ideas but you must bare in mind that it is not simply to name something to make but how do you make it, and with which materials?

Answer 1

Here's something incredibly fun, and so easy to make, it's called a Cartesian diver.
Take a 2 liter plastic soda bottle with clear sides and fill it with water (but not all the way). Put some rubber bands on the bottom or some wire loops. Then for the diver you need a pen cap with a little paper clip attached to it for the hook (you can attach it with a piece of clay.) Or you can use a drinking straw folded in half, or I have even seen a soy sauce packet. Screw cap the bottle very tightly. The diver will be floating on the surface. when you squeeze the bottle, the bubble in the diver will compress and the whole thing will submerge to the bottom.. try to pick up the bands and loops -- I did this with my son for his science fair when he was young and it was lots of fun and a big hit!!

I found this in a book, this one closely approximates it
http://www.sciencebob.com/experiments/cartesian.html
and here are some websites with similar devices:
http://bizarrelabs.com/cart.htm
http://www.sciencetoymaker.org/diver/assembl.html
http://www.worthingtonlibraries.org/NoFlash/kids/science1.htm
http://www.icehouse.net/lchs/ps_2/ws13.html
http://www.leisureideas.com/science/ss_78.htm
http://scifun.chem.wisc.edu/HOMEEXPTS/diver.htm

Answer 2

sounds quite heavy going for a 5yr old.

Just use some lego, the poor lad should be enjoy making fun simple things, not this complex stuff.

Just use 5 or 6 old toilet / kitchen roll tubes, a small card board box. These are rollers on which to move the box, just like people did with stone years ago.

He has to learn to move the ones at the back to the front, etc. simple learning.

Answer 3

he could compare how different kinds of balls move. for example, bounce a tennis ball, a golf ball, and a baseball. why do they bounce differently. or kind of the same idea, but why do they roll differently. does one kind of ball roll farther, why? you can use any kind of ball you want/have-basketball, baseball, golf ball, bouncie ball, beach ball, etc.

Answer 4

hey ummmm how about a balloon car...it moves also.........you can use a balloon,straw,like a meat try cut it and soda bottle tops