1. 4th grade Physical Science Part 2
L.O. I will describe how magnets and electromagnets work.

2. DAY 1

3. Magnets will attract certain metals
Permanent magnet – an object that keeps magnetism for a long time
Temporary magnet – will lose magnetism after a short time
*Magnetic Poles – areas where the force of the magnet is greatest

5. *Bar and horseshoe magnets – pole is at the ends
Ring magnet – pole is on the face

6. *A compass is a free floating magnet that will always point North
*Like poles REPEL – push away
*Opposite poles ATTRACT – pull together S N N

7. Magnetic Earth Earth’s center is made up mostly of molten iron
As Earth spins, the iron particles line up, producing Earth’s magnetic field
*So Earth is like a gigantic bar magnet
*It is surrounded by a magnetic field with lines of force

8. Day 2

9. *Electricity can produce magnetic fields
This is called an electromagnet
When the electric current passes through the wire, the current produces a weak magnetic field around the wire
Iron nail
wire
Power source
switch

10. *To make the electromagnet stronger you can
*wrap more wire around the iron nail
*use more batteries or bigger batteries
If I take the batteries out or turn the switch off, the nail loses it magnetism

11. *Electrically charged objects will become a magnet and will either attract or repel
A motor will make a fan move
*An electric motor changes electrical energy into energy of motion
They use electromagnets and permanent magnets by using like poles to repel and the opposite poles to attract, making the motor move
*Electrical energy will convert to light, heat, and motion