SIMPLE AND COMPLEX MACHINES

What is a simple machine?Simple machines are tools that make work easier. They reduce the effort needed to do work. They have one or two parts.

There are many different simple machines but they can be divided into 3 main types:

1. Levers2. Inclined planes

3. Pulleys

LEVERSA lever is a rigid bar with a pivot point. When we do work, a lever has 2 forces: an effort and a resistance.

EFFORT

PIVOT POINT

RESISTANCE

LEVERSMany simple machines that we use every day are examples of levers.

R

R

R

PP

PP

PPE

E

E

INCLINED PLANESAn inclined plane is a ramp used to lift and lower objects. It makes work easier by reducing the effort necessary to lift or lower an object.

PULLEYSA pulley is a wheel with an axle in the centre and a rope that runs around the outside. We use it to lift or lower objects.

axle

wheel

rope

effort

What is a complex machine?Complex machines have many parts and combine 2 or more simple machines. Each part of a complex machine has a different function.

What is a complex machine?How does a tricycle work?It contains simple machines as well as other parts.

What makes machines work?All machines need energy to work. There are different types of energy.

The most common types are:

- Energy from people and animals

- Energy from electricity

- Energy obtained by burning fuels

Energy from people or animals

What makes machines work?

Many simple and complex machines get the energy they need to work from people or animals.

Many complex machines use electrical energy from mains electricity or from batteries.

What makes machines work?Energy from electricity

Many complex machines burn fuels, wood or biomass to get the energy they need.

What makes machines work?Energy from burning fuels