Sample Fields of Attraction and Poles (grades 5-7) Worksheet
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Fields of Attraction and Poles
By Trista L. Pollard
1 The fields are alive with the spark of attraction! We have all heard the saying "opposites attract," but how far away can they be before they attract? The answer lies in magnetic fields of force. A magnetic field of force is the invisible area around a magnet where the force of the magnet can be felt. This field of force allows the magnet to attract steel and iron objects without touching them. This invisible field can be inferred based upon how steel and iron objects react to the magnet from a distance. For example, if you place a paper clip on a table near a magnet, the paper clip will be drawn into the field of force, therefore moving towards the magnet. Attraction from a distance has occurred.
2 Magnets come in a variety of shapes and sizes. Common shapes are bars, letters (u and v), horseshoes, and cylinders. The field of force, which is strongest at the poles or ends of the magnet, surrounds the entire magnet. Magnets that are shaped like u's, v's, and horseshoes are more powerful than other types of simple magnets. As you may have guessed, when you have two poles to attract objects instead of one pole, the magnet's pull is much stronger. How do we locate the boundaries of a magnet's field of force? Well, the field of force around the magnet goes on for an infinite distance beyond where the human eye can see. So for our investigation purposes, we can say the magnet's field of force ends when we are no longer able to see its effect on steel and iron objects, such as a paper clip.
3 We know that the field of force surrounds a magnet, but does that field travel through other materials to attract objects? What do you think would happen if you put a paper clip in the palm of your hand and held a strong magnet against the back of your hand? Well, if you said the paper clip would move, you would be right. Magnetic fields of force can go through many types of materials, like your hand, without losing its power of attraction. Those materials and your hand are "transparent'' to the magnetic field's lines of force. This means that the magnet's power of attraction can go through your hand and attract an iron or steel object within its field of force. Now you understand why people can wear magnetic earrings on their earlobes. Plumbers also use this scientific principle to help them locate iron pipes in closed walls. Iron and steel, however, are opaque to a magnetic field's lines of force. When a magnet touches an iron or steel object, the force passes to the inside of the object and back into the magnet causing an attraction.
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