Remember, as a member of the Science Bus Club you can ‘Ask Albert’ a question about any of the topics. So if you’re not already a member join today!!
Exploring Magnets
We all know they exist, everyone at some time or other has played with them and they are great fun.
There are forces between magnets and magnets can attract (pull towards) and repel (push away from) each other.
Not all materials can be magnetic; plastic for instance cannot be a magnet. Some rocks are magnetic because there is metal in them, like iron. Even some metals are not magnetic, aluminium for instance.
The biggest magnet is the earth itself, because in the centre of the earth there is molten metal (like the stuff you see spewing out of a volcano). This molten metal gives the whole planet magnetism.
Look around your house and see if you can tell what materials will be attracted to a magnet. Better still try for yourself!!
Magnets are said to have two different ’poles’, “opposite” poles attract (they pull together) “like” poles repel (they push apart).
Magnets can be generally divided into 3 common shapes:-
Bar magnets
Horseshoe magnet- Ring magnets (like donuts)
Finding Magnetic Materials
Its easy to find out what is magnetic. Gather as much ‘stuff’ as you can and test to see if it is magnetic. You will need a magnet to test these materials. If they ‘stick’ to the magnet then they are attracted to the magnet and as such they are magnetic.
Once you have ‘tested’ all your materials group them in two piles, magnetic and non magnetic. What do you notice? You should notice that the magnetic group are metals of some kind or other and the non-magnetic are non metal. That’s really important to know!!!
Uses Of Magnets
Magnets are used everywhere and are essential in our lives.
Did you know that electricity and magnetism are very closely linked?
Some of the uses of magnets include:-
- Work that goes on in scrap metal yards (sorting metal and moving it around)
In hospitals some of the equipment used in the diagnosis of cancer are big magnets. Next time you see your doctor ask him about an MRI Scanner
I bet you have fridge magnets in your house too.
Explorers use magnets that interact with the “magnetic field” of the earth to show them the direction they are travelling in.
Have you ever seen a compass? This is affected by the “magnetic field” of the earth.
The speakers in your television or CD player or Ipod use magnets too.
Try to find out other uses for magnets and list them.
Behaviour Of Magnets
Magnets can have different strengths, for fun try this:-
Get a pile of paper clips and different magnets. See which magnet picks up the most paper clips- Its better if the magnets you use are the came shape
- The magnet that picks up the most paper clips is the strongest
Don’t forget to log your results.
Remember “opposite” poles attract. Do you remember what “like” poles do?
Use Of Springs
Like magnets, springs are everywhere too.
How about these springs:
Playground rides; you know the ones you sit on? This will have a big spring underneath it.
Do you have a trampoline or have you ever been on one? Well that’s also a spring.
Did you know that many clocks are controlled by springs?
Did you ever see a stapler on your teacher’s desk? Well that opens and closes with a spring.
Cars, trucks and buses have springs too to absorb the shocks when they go over bumps in the road.
Sometimes on doors you see springs that close the door when you forget to!!!
If you have a pen that you ‘click’ (so the point comes down so you can use it), well that too is controlled by a spring.
Elastic bands are springs also.
Compressing And Stretching Springs
If you apply a stretching force to a spring the longer it will get (the harder you stretch it the longer it will get). Applying a lesser force will result in a shorter distance.
You can also compress a spring, in other words push it in on itself. The harder you compress the spring the smaller it gets. If you apply a smaller compression force it won’t be as small.
Below are images of magnets and springs
Remember, as a member of the Science Bus Club you can ‘Ask Albert’ a question about any of the topics. So if you’re not already a member join today!!
