SIMPLE AND COMPLEX MACHINES
MACHINES ARE OBJECTS THAT HELP US TO DO THINGS
SIMPLE MACHINES WORK VERY SIMPLY.
SIMPLE MACHINES REDUCE THE AMOUNT OF FORCE WE NEED TO APPLY TO COMPLETE A TASK.
COMPLEX MACHINES ARE MADE OF MANY SIMPLE MACHINES. MACHINES NEED ENERGY TO WORK.
SIMPLE MACHINES:
WEDGE: WE CAN USE THE SHARP PART OF THE WEDGE TO CUT THINGS MORE EASILY.
WHEEL AND AXLE: THE WHEEL REVOLVES AROUND THE AXLE AND CAN MOVE THINGS EASILY.
SCREW: IT IS AN INCLINED PLANE THAT GOES AROUND A CYLINDER OR CONE. WE USE IT TO HOLD THINGS TOGETHER.
RAMP: IT IS AN INCLINED PLANE.
WE USE RAMPS TO PUSH HEAVY OBJECTS UP AND DOWN WITHOUT LIFTING THEM OFF THE GROUNG.
PULLEY: IT IS A WHEEL THAT TURNS ON AN AXIS. A ROPE GOES AROUND THE WHEEL.
WE USE PULLEYS TO LIFT HEAVY OBJECTS MORE EASILY.
WE PULL THE ROPE AT ONE END AND THE OBJECT RISES AT THE OTHER END.
LEVER: IT IS A RIGID BAR.
WE USE LEVERS TO PUT FORCE ON A POINT OF SUPPORT AND LIFT OBJECTS.
LEVERS HAVE THREE MAIN PARTS:
POINT OF SUPPORT
LOAD: RESISTANCE TO OUR FORCE
EFFORT: FORCE THAT WE USE.
THERE ARE THREE TYPES OF LEVER:
CLASS 1: POINT OF SUPPORT IS IN THE MIDDLE.
CLASS 2: LOAD IS IN THE MIDDLE.
CLASS 3: EFFORT IS IN THE MIDDLE.
COMPLEX MACHINES
WE CAN CLASSIFY THEM BY THEIR FUNCTION. THEY CAN BE: MECHANICAL, THERMAL OR THEY CAN PROCESS INFORMATION.
MECHANICAL MACHINES: MAKE THINGS MOVE USING A MOTOR OR ENGINE. THIS ENGINE TRANSFORMS THE ELECTRICITY OR FUEL INTO KINETIC ENERGY (MAKE THINGS MOVE).
THERMAL MACHINES: MAKE THINGS HOT OR COLD. FOR EXAMPLE, AIR CONDITIONERS AND HEATERS.
INFORMATION PROCESSING MACHINES: THESE MACHINES ARE USED FOR COMMUNICATION AND CALCULATIONS. FOR EXAMPLE, COMPUTERS, MOBILE PHONES AND CALCULATORS.
MACHINES NEED ENERGY TO WORK
SOURCES OF ENERGY:
ENERGY FROM PEOPLE
RENEWABLE ENERGY SOURCES
ENERGY FROM FUEL
ENERGY FROM ELECTRICITY AND BATTERIES.
SOME MACHINES NEED TO BE CONNECTED TO ELECTRICITY SUPPLY THROUGH A PLUG OR SOCKET.
ELECTRICITY
ALL MATERIALS CONTAIN ELECTRICAL CHARGES. ELECTRICAL CHARGES CAN BE POSITIVE OR NEGATIVE.
STATIC ENERGY
WE PRODUCE STATIC ENERGY WHEN WE RUB TWO NON-METAL OBJECTS.
OBJECTS WITH THE SAME ELECTRICAL CHARGE REPEL EACH OTHER.
OBJECTS WITH OPPOSITE ELECTRICAL CHARGES, ATTRACT EACH OTHER.
CURRENT ELECTRICITY
WHEN AN ELECTRICAL CHARGE MOVES IN AN ELECTRICAL CONDUCTOR, WE HAVE CURRENT ELECTRICITY. THE MOVEMENT OF ELECTRICAL CHARGES IS CALLED ELECTRICAL CURRENT.
ELECTRIC CIRCUIT
THE PARTS OF AN ELECTRICAL CIRCUIT ARE CONNECTED TOGETHER. THE ELECTRIC CURRENT CAN ONLY PASS TROUGH A CLOSED CIRCUIT.
PARTS OF THE ELECTRIC CIRCUIT:
GENERATOR: SUPPLY ELECTRICITY.
CONDUCTORS: LET ELECTRICITY PASS THROUGH THE CIRCUIT (METAL WIRES COVERED IN AN INSULATING MATERIAL).
ELECTRICAL COMPONENTS: TRANSFORM ELECTRICITY INTO ANOTHER FORM OF ENERGY.
EXAMPLE: A LIGHT BULB TRANSFORMS ELECTRICITY INTO LIGHT.
SWITCHES: OPEN AND CLOSE THE ELECTRIC CIRCUIT.
WE CAN CLASSIFY THEM BY THEIR FUNCTION. THEY CAN BE: MECHANICAL, THERMAL OR THEY CAN PROCESS INFORMATION.
MECHANICAL MACHINES: MAKE THINGS MOVE USING A MOTOR OR ENGINE. THIS ENGINE TRANSFORMS THE ELECTRICITY OR FUEL INTO KINETIC ENERGY (MAKE THINGS MOVE).
SOURCES OF ENERGY:
ENERGY FROM PEOPLE
SOME MACHINES NEED TO BE CONNECTED TO ELECTRICITY SUPPLY THROUGH A PLUG OR SOCKET.
ELECTRICITY
ALL MATERIALS CONTAIN ELECTRICAL CHARGES. ELECTRICAL CHARGES CAN BE POSITIVE OR NEGATIVE.
WE PRODUCE STATIC ENERGY WHEN WE RUB TWO NON-METAL OBJECTS.
OBJECTS WITH OPPOSITE ELECTRICAL CHARGES, ATTRACT EACH OTHER.
WHEN AN ELECTRICAL CHARGE MOVES IN AN ELECTRICAL CONDUCTOR, WE HAVE CURRENT ELECTRICITY. THE MOVEMENT OF ELECTRICAL CHARGES IS CALLED ELECTRICAL CURRENT.
THE PARTS OF AN ELECTRICAL CIRCUIT ARE CONNECTED TOGETHER. THE ELECTRIC CURRENT CAN ONLY PASS TROUGH A CLOSED CIRCUIT.
GENERATOR: SUPPLY ELECTRICITY.
EXAMPLE: A LIGHT BULB TRANSFORMS ELECTRICITY INTO LIGHT.
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