The six kinds of simple machines Select a lesson
what are the human senses

Define a simple machine
types of machines
explain an inclined plane for children Explain a wedge simple machine
Explain a screw simple machine Explain a lever simple machine
Explain the wheel and axle simple machine
What is a pulley simple machine
Terminology on simple machines


Asexual Reproduction
Charact' of Living Things
Elements, mixtures, comp.


Needs of Living Things
Nutrients in Food
Rock Cycle
States of Matter
The Five Senses
Water Cycle
The Lever simple machine

Types of machines

Machines come as two major kinds —
Simple Machines and Complex Machines.

Simple Machines
A simple machine is a tool, device or object with few moving parts that help us do work. Simple machines have been in use for a very long time. Early humans used simple machines to push, pull, lift, divide and crush things. They used simple machines to row rafts over water, build houses, split firewood, and carry heavy things from place to place. Today, there are simple machines in every place and all around us.

Kinds of simple machines

There are six types of simple machines — the inclined plane, the wedge, the screw, the lever, the wheel and axle, and the pulley. These six have very specific features and do unique jobs, even though some may work in similar ways. In fact, some simple machines may be a combination of simple machines.

Simple machines, unlike complex ones, do not work on their own. They only increase the pull or push, (force or effort) that a person uses, increase or decrease the distance, or change the direction of a movement so that more work can be done. They can:
Class of leverstransfer a force from one place to another
Class of leverschange the direction of a force
Class of leversincrease the magnitude of a force
Class of leversincrease the distance or speed of a force

Features of a simple machine
Class of leversThey do not use electricity
Class of leversThey have one or fewer moving parts
Class of leversThey give us mechanical advantage
Class of leversEven though they make work easier for us, they still need input (force or effort) from a person.
Class of leversThey make tough jobs easier by changing the force, direction or speed of a movement

Complex Machines
Simple machines are different from complex (or compound machines). Complex machines, like trucks or wagons, or bicycles use many moving parts. They combine many simple machines such as levers, pulleys, and gears to get work done.

Now, we shall look at each example of a simple machine.

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pulley  simple machines