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πŸš€ Inventions and machines πŸ”§ Machines and tools

Machines

How a machine changes the direction of movement
How a machine changes the direction of movement

πŸ“– In short

A machine is a device that helps us do work more easily. Some machines are very simple, like scissors and pulleys, and some are very complicated, like cars, planes and computers. Factories are full of machines that make the things we use every day.

🀩 Did you know?

  • Some machines waste a lot of their energy as heat, so their efficiency is low.
  • A machine's performance is measured by its efficiency and its mechanical advantage.
  • A wheelchair ramp is an inclined plane, which is a simple machine.
  • The thread on a jar lid is a simple machine too!

πŸ”Ž Find out more

🌟 Simple machines

There are six simple machines: the lever, the pulley, the wheel and axle, the inclined plane, the wedge and the screw. All complicated machines are made of these simple machines.

πŸ” How do they help us?

Some machines make a small force bigger, so we lift heavy loads with little effort. Others make movement faster, and others change the direction of a force, like a pulley where we pull the rope down and the bucket goes up.

πŸ’‘ Power source

Machines need energy to work: from our muscles, from animals, from wind and water, or from petrol and electricity.

🎯 Machines and people

Machines have made work easier and faster: a tractor plows a field in hours instead of days. But it's people who design, run and repair the machines.

πŸ“Έ More pictures

The lever is one of the first simple machines. Its advantage comes from the short distance between the pivot and the load, and the long distance between the pivot and the point where effort is applied.
The lever is one of the first simple machines. Its advantage comes from the short distance between the pivot and the load, and the long distance between the pivot and the point where effort is applied.
The wheel and axle has a rope tied to the axle to lift the load, and the crank handle is where effort is applied. The effort is smaller than the load because the handle is far from the axle, which is the pivot.
The wheel and axle has a rope tied to the axle to lift the load, and the crank handle is where effort is applied. The effort is smaller than the load because the handle is far from the axle, which is the pivot.
A pulley is a wheel with a groove around its rim that a rope runs in. A pulley is used to change the direction of the effort applied at the end of the rope. And a block and tackle, with two or more pulleys, is used to reduce the effort needed to lift a load.
A pulley is a wheel with a groove around its rim that a rope runs in. A pulley is used to change the direction of the effort applied at the end of the rope. And a block and tackle, with two or more pulleys, is used to reduce the effort needed to lift a load.

🧩 Test yourself

1 How many simple machines are there?

2 Which of these is a simple machine?

3 Which picture shows β€œMachines”?

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