3 Let’s bet! Is a/an………..a machine? Write questions for all the objects and bet (from 1 to 5).QuestionYes, it is a machine.No, it isn’t a machine.BETLOSSGAIN1. Is a TV a machine?184.108.40.206.220.127.116.11.10.11.12.13.18.104.22.168.18.19.20. Are scissors a machine?TOTAL:Is a drier a machine?Is a cheese grater a machine?Is a computer a machine?Is an apple a machine?Is a screw nut a machine?Is a tow truck a machine?Is a book a machine?Is a washing machine a machine?Is a telephone a machine?Is a corkscrew a machine?Is an axe a machine?Is a see-saw a machine?Is a well a machine?Is a slide a machine?Is a radio a machine?Is an artichoke a machine?Is a police car a machine?Is a dog a machine?Grand total=
4 IT CAN WORK WITH MECHANICAL ENERGY WHAT IS A MACHINE?It is a device designed to make work easier.IT CAN BE SIMPLEIT CAN WORK WITHWIND ENERGYIT CAN BE COMPLEXOR COMPOUNDIT CAN WORK WITHELECTRICITYIT CAN WORK WITH MECHANICAL ENERGYIT CAN WORK WITHSUN ENERGYIT CAN WORK WITH CHEMICAL ENERGY
5 WHAT IS WORK?WORK is done when a FORCE moves something. If you use a PUSH or a PULL to move an object you are doing WORK.PUSHPULLFORCEOBJECT
6 When we do work we use energy. Law of conservation of energy.“Energy can neither be created (produced) nor destroyed by itself.It can only be transformed.”
7 HANDS ON! EXERCISE 1 LEVER CAN WE LIFT THIS PENCIL?CAN WE LIFTTHIS CHAIR?CAN WE LIFTA CAR?
11 LOADA big rockLOADBobEFFORTLong stickLEVERSmall rockFULCRUMYes, Bob can lift the rock with the help of the stick and the small rock. A STICK + A SMALL ROCK= A SIMPLE MACHINE IT IS CALLED A LEVEREFFORTLEVERFULCRUM
12 At an appropriate distance the big rock moves easily. LOADEASY TO MOVEEFFORTLEVERAt an appropriate distance the big rock moves easily.FULCRUM
13 At an inappropriate distance the big rock doesn’t move. LOADDIFFICULT TO MOVEEFFORTLEVERFULCRUMAt an inappropriate distance the big rock doesn’t move.
14 HANDS ON! LEVER Ask some questions about the experiment. PROBLEM:Can we do the same work with less effort?How many rulers do we need?We need two rulers: one long and one short.What do we do with the rubber?We use the rubber as a fulcrum for doing a lever.What is the big book for?We use the big book as a load.Which ruler do we use first?Start with the short ruler and then do the same process with the long ruler.What are the small books for?We use the small books as an effort.What is the ruler for?We use the ruler as a lever.
15 HANDS ON! LEVER MATERIALS Write down the materials that you need to create the lever.Long rulerShort rulerA rubberA big bookSmall booksA pencil
16 HANDS ON! LEVERSTEPS1. Predict: What is the best position of the rubber (as a fulcrum) to lift the big book with less effort (less small books)?Predict: Which is the best ruler for lift the big book with less effort?2. Prepare all the materials.3. Start with the short ruler.4. Try different positions for the rubber (fulcrum).5. What is the best position of the rubber (as a fulcrum) to lift the big book with less effort (less small books)?6. Change the short ruler for the long ruler and repeat the process.7. What is the best ruler to lift the big book with less effort?
17 What is the best position of the rubber (as a fulcrum) to lift the big book with less effort (less small books)?Known asPosition number 1
18 What is the best ruler to lift the big book with less effort? It is the long ruler because it multiplies the effort applied.
20 “Give me a lever long enough; a fulcrum strong enough and I’ll move the world.” Archimedes
21 LAW OF THE LEVER“Magnitudes are in equilibrium at distances reciprocally proportional to their weights.”ArchimedesForça, Equilibri, Valor i Seny!Force, equilibrium, courage and wisdom!
22 LEVERIt’s a rigid object that is used with an appropriate fulcrum to multiply the effort applied on a load.Fulcrum: a support on which a lever pivots.Load: resistance force (weight and gravity).Effort: force needed to move an object.
27 INCLINED PLANEIt is an inclined surface used to raise an object. It decreases the effort.
28 WHEEL AND AXLEIt is a wheel with a rod, called and axle, through its centre: both parts move together.
29 SCREWIt is an inclined plane wrapped around a central shaft. The Rotational motion of the central shaft causes a linear upwards motion of the screw.
30 PULLEYIt is a wheel or set of wheels around which a single rope passes to move a load with a smaller effort.
31 WEDGEWedges are moving inclined planes which split or separate a load.
32 MACHINES SIMPLE MACHINES LEVER SCREW PULLEY WEDGE HOW IT HELPS US WORK?MACHINESSIMPLE MACHINESPLIERSSCISSORSTO LIFT OR TO MOVE LOADSLEVERTHINGS MOVE UP OR DOWN ITINCLINED PLANETO MOVE LOADSWHEEL AND AXLETO HOLD THINGS TOGETHER OR TO LIFTSCREWTO MOVE THINGS UP, DOWN OR ACROSSPULLEYTO CUT OR SPREAD AN OBJECT APARTWEDGE
33 They are any combination of simple machines. To know more aboutSimple machinesCompound machinesThey are any combination of simple machines.Two leversTwo wedgesSCISSORS
34 LET’S FIND MACHINES IN OUR SCHOOL PUPILITS NAMEWE CAN USE IT TO…WE CAN USE THE……. TO…NAME OF THE SIMPLE MACHINE MARIAJOSEP1 SCISSORSWE CAN USE THE SCISSORS TO CUT DIFFERENT THINGS LIKE PAPER. 2 LEVERS2 WEDGES2345678
36 OUR SIMPLE LAWN-SPRINKLER A ROCKING CHAIR ( A )SQUEEZES A BULB ( B )SPRAYING A SHIRT ( C )THIS CAUSES IT TO SHRINK AND PULL THE STRING( D )TIPPING THE SHELF (E)THE HOMEMADE BISCUIT ( F )FALLS HEAVILY INTO THE NET (G )CAUSING THE ROD ( H )TO RAISE A COVER ( I)EXPOSING A MOUSE ( J )A CAT CHASES THE MOUSE ( K )THEREBY REVOLVING THE PLATFORM (L)EACH TIME THE LAUGHING HYENA (M )REVOLVES HE IS TICKED ON THE NOSE BY FEATHER BALL ( N )CAUSING HIM TO LAUGH SO HARD HE CRIES – THE SPEED OF THE REVOLUTIONS SCATTERS TEARS OVER LAWN CAUSING THE GRASS TO GROW.
37 Some examples of compound machines Some school projectsDifferent materialsPythagoras switchAdvertisementsTo look at the purpose To look at the materials To look at the idea Amazing !
38 Step-by-step process to build a compound machine PhaseStepWhat do you do?Choose two partners1FirstSecondChoose a theme for the machineThirdMake a drawing/ sketch of a machineFourthWrite a list of materials and tools needed.2FifthMake the machine.SixthMake two lists one for the verbs and one for the nouns.SeventhUse verbs to describe the action of the parts of the machine.Order the different parts of the process.EighthWrite the steps of the movement of the different parts of the machine.Ninth3Explain the machine function to other groups.TenthFinallyGive your opinion as a group about the process of building the machine.