Technology

Every invention requires the work of many people. The wheel  is a fundamental piece of thousands of other inventions. No one knows who invented it, or exactly when it was first used, but we can't imagine a world without wheels.

Machines make our lives easier by saving us time and energy. We can distinguish 2 types of machines: Simple machines and complex machines

1 SIMPLE MACHINES

Simple Machines are basic mechanical devices that make our work easier. 

They 

reduce  the effort that you need to do something, by applying a force they make a work.  They have few or no moving parts.

 

  

    

    

Four examples of simple machines:

• Wheel and axle: We use them to move things across the ground more easily.

• Screw: We use them to hold things together or lift objects.

• Pulley: This machine has a wheel and axle and a rope. When we pull down on the rope, we lift an object that is attached to it.

• Lever and fulcrum: This machine is a rigid bar which turns on a support called a fulcrum. When we push one end of a lever down, the opposite end moves up.

2 COMPLEX MACHINES

When we put two or more simple machines together 

we get a complex machine. Some machines also have an engine .

• Engine: It is the part of the machine that produces movement.

• Gears: They are wheels with teeth that fit together. When one wheel turns the other one turns too, but in the opposite direction. We can find gears in windmills, clocks and watches, and toys with motors.