MACHINES

Alejandro 4º A

SIMPLE MACHINES

• A machine is something we use to make work easier. We can classify machines as simple machines or complex machines

• Simple Machines: Have few or no moving parts.

Pliers

MORE SIMPLE MACHINES• There are six simple machines:• 1) A pulley, uses a whell and a rope to lift or lower an object.

• 2) An inclined plane, move objects up or down.

MORE SIMPLE MACHINES• 3) A Srew, is a hold things together or lift objects

• 4) A Wheel, turn around an axle. We use it to lift or move objects

MORE SIMPLE MACHINES• 5) A Wedge, we use a wedge to cut objects.

• 6) A Lever is a rigid bar with fulcrum. We use it to lift or move objects.

COMPLEX MACHINES

• Complex Machines are made up of a number of simple machines working together.

• Complex machines need energy. This energy can come from people, electricity or fuel. We use complex machines every day,complex machines are everywhere.

TYPES OF COMPLEX MACHINES

• Electrical appliances: Some examples are: Washing machines, cookers and calculators in our schools.

• Which energy do they use? They use electrical energy. And some electrical use energy from batteries.

• Forms of transport: Some examples are: Buses, cars, lorries and bicycles.

• Wich energy do they use?• They use the fuel energy, but bike uses people energy. Some are electrical

energy.

TYPES OF COMPLEX MACHINES• Robot at work:• What do we use them for?• They use robots to make mass-produced products, and they do jobs

dangerous for people.• What are the advantages of robots?• The advantages are that are more efficient and safer to use.

THE BICYCLE• A bicycle is a complex machine because it´s made up of some simple

machines working together. It needs kinetic energy.– 1) Handlebars. They are levers that help us change direction.

– 2) Pedals. They are levers. They make the wheels turn around when we push them with our feet.

– 3) Gears. They are pulleys that help us when we have to go up or down a hill.

– 4) Gear Controls. They are levers in the handlebars that are connected to the gears through cables.

– 5) Brakes. They are levers that help us slow or stop the bike. They are in the wheel.

– 6) Brakes Levers. They are in the handlebars and are connected to the brakes through cables.

THE BICYCLE

THE BICYCLES• 1.- The first bicycles were made of wood. They had no pedals and used

their feet to walk at the same time.

• 2.- A bicycle with pedals was invented. This bicycle had metal tyres.

• 3.- A bicycle with a very big front wheel was invented. Its tyres were made of solid rubber.

• 4.- Both wheels were the same size, but wheels were still made of solid rubber.

• 5.- The first bicycle with air in its tyres was invented

THE BICYCLES