3MagnetismIs a force that acts on moving electric charges and on magnetic materials that are near a magnet
4Magnetic Poles Magnets always have two poles. The north pole and the south pole.Why would a N N pole repel?
5Magnetic FieldHow can magnets attract or repel without touching things?Remember a force is a push or pull that can cause an object to move.A magnetic force can be exerted when objects aren’t touching, just like gravity and electric forces.
6Magnetic FieldIn which direction do magnetic fields run?
7Magnetic Field (Slide 1) Magnetic field lines start at a magnet’s north pole and end on the south pole.
8Magnetic Field (Slide 2) Magnetic field lines are close together where the field is strong and get further apart as the field gets weaker.Fields are strongest at the poles.Lines closer together = StrongLines far apart = Weak
9Magnetic Force The magnetic fields create a magnetic force. Magnetic objects exert a magnetic force on each other.This force explains why magnets don’t have to touch to attract or repel objects.Magnetic force gets weaker with more distance between objects (like gravity).Demo- pick up nails with magnet
10Magnetic ForceLook at the picture below, the magnet and the nails are exerting a magnetic force on each other.
11Magnetic ForceHowever, the force gets weaker as it goes through the nails, which is why the magnet does not pick up every nail in the bucket.
12Attraction Opposite poles attract each other. When field lines curve towards each other it shows attraction.
13Repulsion Like poles repel each other. Field lines that curve away from each other show repulsion.