April 3, 2011


An object will stay still or keep moving unless an external force acts upon it.  This is the principle of inertia.  We have been busy doing some experiments to play with inertia this weekend.
We were started on our inertia quest by an experiment in a science kit of my son’s - Magical Marbles (from Science Experiments, by Helen Chapman, Hinkler Books, 2010).SONY DSC
To do the experiment you need 2 rulers, marbles and tape.
Tape the ruler’s to a flat surface as shown in the picture.
Put the marbles between the two rulers about 5 cm apart.
Tap one marble so it rolls and hits the second marble.  What happens?
You will find that the marble that had been rolling stops and the one that had been still, now rolls.  Try it with more marbles – knock one marble into a line of 2 or 3 touching marbles. 
Try knocking 2 marbles into 3 still marbles.
This experiment shows the principle behind Newton’s Cradle.
From here we moved on to a couple of other inertia experiments I remembered reading at Irresistible Ideas for Play Based Learning.     And we did plenty of unplanned ‘what happens if I do it like this?’


Cate said...

Love kids' passion for science - it's just so inspiring!!

PlanningQueen said...

What a super little experiment - thanks for sharing Catherine. My boys will like this.