1. Simple Electric Circuit Magnetism and the Electromagnet Mechanical Systems (revision) Developed by: Johnny Freese WCED: METRO SOUTH CAPS Technology Grade 7 Term 3

2. TYPES OF MAGNETS HORSE SHOE BAR MAGNET MANY TYPES

3. MAGNETISED & UNMAGNETISED UNCOMBED HAIR COMBED HAIR UNMAGNETISED MAGNETISED

4. Some metals are attracted to magnets and some are not. iron aluminium nickel steel wood copper plastic

5. Simple Electric Circuits

6. A simple electrical circuit 3 volt batteryswitch Light bulb Conducting wire 1,5 V

7. Simple circuit diagram 1,5 volt cell Conducting wire switch Light bulb

8. Summary Component NameComponent PictureSymbol Cell Switch Light Bulb Conducting wires 1,5 V

9. Simple Electro-Magnet

10. Simple electromagnet N S Iron nail Cell Switch Insulated copper wire

11. Magnetic force! More windings mean a stronger magnet 3 layers of windings

12. Explain how this electromagnet machine works. Many technologies use electromagnets.

13. Mechanical Systems and Control (Revision)

14. The Crank is an example of a Second Class Lever Second Class Lever Fulcrum Load Effort Load Fulcrum Effort Crank Mechanism F L E Handle is the effort Axle is the fulcrum The disc (wheel) is the load

15. The Pulley is an example of a wheel and axle Wheel and axle Cart Pulley CA 2545

16. Revision: Mechanical Advantage Load Effort Fulcrum E f f o r t a r m This lever can lift a very heavy load. The longer EFFORT ARM provides mechanical advantage

17. Revision: Strengthening Frame Structures Gusset Bracing We strengthen Frame Structures By using Gussets, Bracing and Triangulation. Triangulation