Teaching Minds-On Experiments on Electromagnetism in Secondary Schools

Permanent magnets
Magnetic rafts. Distance in magnetic interactions

Two magnets are placed upon two small polystyrene rafts floating on water. If we bring the north pole of one of the magnets near to the south pole of the other, we observe that the magnets attract each other. If we bring together the same type of poles (north – north or south – south) we observe that the magnet, which is able to move rotates 180 degrees in order to attach itself to the opposite pole of the other one.
Distance influences the interaction between magnets. The further away the magnets are, the weaker their attraction is, until the point that they are not able to come closer, even when placed on rafts floating on water. When the magnets are close enough the attraction is strong: they attract until they touch.
© University of Udine