Monday, April 02, 2007

Science at home 5

Last night, Sean asked to make a rocket balloon, an experiment he found in his Blue Pocket Scientist book.

As I write this, I realised the last time we conducted an experiment at home was more than 2 months ago. Urggh, so much for my plans to keep Brian up to pace with Singapore's Pri 4 Science syllabus.

Anyway, here's our rocket balloon (materials needed: straw, balloon, tape, string):

Wanna see it again?

Objective: To show that you can use air to move things.
Procedure: Thread a long string through a straw and tie to two chairs. Blow a balloon (preferably a long-shaped one) and peg the end to stop the air from escaping. Tape balloon to straw. Move straw to the end of the string and release the peg.

Outcome: The air trapped inside the balloon pushes out the open end, causing the balloon to move forward.
Explanation: The force of the air escaping is the "action"; the movement of the balloon forward is the "reaction" predicted by Newton's Third Law of Motion "For every action, there is an equal and opposite reaction."

CONCLUSION: Air power can move things.

1 comment:

The Chengs said...

cool! now... let me show our boys. hey, our elder ds is P4 too.