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

DAY 1

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

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

*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

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

Day 2

*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

*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

*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