MAGNETISM

NON-CONTACT FORCES

• A non-contact force acts through a region of space called a force field.

• In regards to gravity:

• Gravitational Field

• When we talk about magnets and the way they interact with objects we need to understand their:

• Magnetic Field

MAGNETS.

1. I want you to get one of the magnets and the magnetic field plate.

1. Place the magnet on the plate

2. In your book I want you to draw a diagram to represent what you see on the plate.

2. In your books I want you to describe the way the magnet interacts with the metal. Describe what you think the structure of the magnet is.

MAGNETIC FIELDS

• A Magnet pulls or Attracts materials containing:

• Iron, Cobalt and Nickel

• Things are only attracted when they are positioned within an objects magnetic field

• The magnetic field is “The space around a magnet where a magnetic force is experienced”

• Magnets ends are called “poles”.

• When placed in water the one that rotates to point north is called the North Pole

• The opposite end is the South Pole

Magnetic Field lines:

• Show the direction that a compass would point

• Always run from the north pole to the south pole

• Do not cross

• Represent a strong magnetic field when they are bunched together

• Represent a weak magnetic field when they are spread apart

EARTHS MAGNETIC FIELD

http://www.youtube.com/watch?v=FcfWsj9OnsI http://www.youtube.com/watch?v=izYiDDt6d8s

ATTRACTION AND REPULSION

• Magnetic Poles may be attracted to each other:

• Complete the following table and then write a statement to describe what is happening.

Ends Attracted or Repulsed

South and South

North and North

North and South

“Like poles will repel each other away, whereas Opposite poles will attract.”

TYPES OF MAGNETS

• There are two types of magnets:

• Temporary: Those that act as a magnet for a short period of time (Electromagnets)

• Permanent: Magnets that are magnetic for a long period of time

http://www.youtube.com/watch?v=noGGcyPHtdI

http://www.youtube.com/watch?v=aIwbrZ4knpg