I am at my workbench and bored , so i;m doing a little experiment. I have one allan key and one magnet, when I move the maget close to the allan key there is no attraction, until I get a certain distance away,(say 2 cm's for aguements sake) then the allan key zooms towards the magnet so fast I cannot pull the magnet away fast enough.
This happens as well if i go really really slow, no attraction then bamm, the allan key is stuck to the magnet.
How comes I cant get to a distance where the allan key is slowly attracted to the magnet, so i can pull the magnet away and they both move at the same speed.
2006-11-30 00:05:33 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Physics
There's two reasons for the sudden "leap" of your allen key towards the magnet.
Firstly, magnetic force is proportional to the inverse square of the distance over which it acts. (to put it another way, if you halve the distance, the force is quadrupled).
Secondly, the friction force between your allen key and the bench becomes much less when the allen key starts moving (this is called mu (mew) slip).
Yes, it is possible to maintain a distance which will continually pull the allen key along. It's a case of balancing the force of attraction from the magnet and the friction force. This is a whole lot easier to do if the friction force is proportional to the speed of movement, so that the faster it goes the more force there is holding it back. One way to achieve this is to put your allen key in a little boat on some water.
Best regards.
2006-11-30 00:21:59 · answer #1 · answered by chopchubes 4 · 0⤊ 0⤋
This is to do with the magnetic field intensity around the magnet. It is uniformly distributed, flowing from pole to pole, but the intensity of the field increases not linearly but exponentially - involving value where x is raised to the power of two, for example. But as you get closer to the core of the magnet, and if you mover very slowly you can record the sudden increase in magnetic pull upon the object you are using for your experiment. This is just like the basin of a lake, where the depth of the water may not increase absolutely suddenly as if there were edges at the right angle to the surface of the flat bottom of the lake. The edges instead may fall very steeply into the depth leaving you a very little time to realise that you stepping into deeper waters. The same fact is observable in gravitational field around the Earth. Once out of that zone satellites can stay in an orbit. They have to exert enormous amount of power to escape from that zone. The speed required for this is called escape velocity – about 7 miles per second. On the other hand the gravitational pull of the Earth becomes suddenly many times over at a certain altitude.
2006-11-30 08:31:04 · answer #2 · answered by Shahid 7 · 0⤊ 0⤋
The reason this happens is due to the coefficient of friction between the allen wrench and the desktop. The coefficient of friction is larger when the allen wrench is at rest --- it is smaller when the object is moving.
Thus, as you initally put the magnet close to the allen wrench, the frictional force is greater than the magnetic force until they are both same. At that point, the allen wrench begins to move. The friction force then becomes small compared to the magnetic force and so the allen wrench starts to accelerate. Since the magnetic force is exponentially stronger with shorter distance, the allen wrench continues to accelerate.
You can get the allen wrench to move slowly towards the magnet -- if you reduce the coefficient of friction. (Try a little oil or WD-40 and a plastic surface --- and you'll notice a big difference.)
2006-11-30 08:23:41 · answer #3 · answered by Sam I AM 3 · 0⤊ 0⤋
You could only do it if your reactions were about 1000 times faster than they are. The acceleration due to the force reaching the required strength to pull the allen key along is faster than your response. Also, to pull the allen key along, you'd have to make extremely sensitive movements in order to not pull the magnet too far away (so the allen key fell outside the zone of attraction and stopped moving again) or not far enough (so the two touched)
Simple answer is you're an animal, not an electromagnetic robot, and your senses are not refined enough to carry out the task...
2006-11-30 08:13:32 · answer #4 · answered by Alyosha 4 · 1⤊ 0⤋
The key to this mystery as Poirot would say, is there before your eyes.
Like all good people the eyes seldom see what they are looking at. As my long dead uncle would say.
Ah so! To the point.
The Allen key is on the desk? Yes.
It resists the magnetic field ? Yes? Well no it doesn't.
The desk's rough surface is holding it to its surface and when the magnetic field increases it pulls it away in a whisker.
All magnets have fields of varying shapes.
Some are Polar and some elongated to look like bananas.
Excuse my humorous delivery. It's my age.
2006-12-01 06:59:38 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Maybe you should try damping the magnetic field by putting a non conductive element in front of the magnet.
2006-11-30 08:17:36 · answer #6 · answered by Crazy Diamond 6 · 0⤊ 0⤋
You can but your hand is not accurate enough, the point where it happens is very thin!
2006-11-30 08:09:04 · answer #7 · answered by davespnr 2 · 0⤊ 0⤋
I THINK YOU NEED TO GO DOWN THE PUB
2006-11-30 08:13:16 · answer #8 · answered by Anonymous · 0⤊ 1⤋