Now start to look at the very strange world of magnet and their forces of attaction and repulsion.
Youtube video, suitable whether of not you have the board with you.
See board images.
Tutorial guide for when you have the board with you.
The world of magnetism is really mind blowing. Here is a simple start, we can see the steel ball bearing being pulled towards a very large magnet. If we give it all a little a shake, we will see they swing around and slowly come back to their position closest to the magnet – pulled by the magnetic force between the steel and the magnet.
This second board drills down into magnetism a bit more. Look at the top slot first, the left slider is made of steel. As we pull the righthand slider, which is a magnet, it pulls the other one because we have an attractive force between the two.
Now the ends of a magnet have names, they are called the south and north poles. This is because the whole planet is just one big, massive magnet and if we let a magnet swing freely, the north pole end of the magnet will pull round to face an area of the planet very close to the north pole. While we think about that, let’s get back to the board, look at the third slot, this has two magnets, one with the north pole at the top and one with the south pole. These will attract each other so they will ‘stick’ to each other as we pull the right side one across the board.
But now let’s look at the second slot, here two south pole magnets are facing us so this time the magnetic forces means they repel each other. As we push the righthand one across the slot the other one keeps away from it. In the last slot we have three magnets instead of one and this means the force is stronger and the two stay further away from each other.
Each of the magnetic sliders has magnets on the front and back of the board, if these had faced each other with a south and a north pole, the force pulling them together would make it very difficult to pull them along the slot, so the bottom magnet is turned round so they are repelling each other and making it easier to slide them.
Magnets will lose their magnetism over a period of time if they are not being attracted to something. So, we often have a bit of steel around which we stick on the magnet when we are not using it. This is called a ‘keeper’. I used some old washers, but I must check they are ones made from mild steel, the ones I have that are stainless steel will not work!
Try and find two magnets (you might have some of a fridge) and try and get them to attract and repel each other. You might find that the fridge door is held closed by magnets round the edge.
Some follow-up ideas to try...