Wheels, Axles,
and Pulleys
Vocabulary
Read the vocabulary terms to understand the reading better.
Gears
Gears are wheels with teeth that slot together. Gears are found in cars and bicycles.
Load
The load is the object being moved or lifted.
Pulley
A pulley is a simple machine that has a wheel over which a belt, rope, or chain is pulled to lift or lower an object. You can use a pulley to raise or lower blinds on a window.
Simple Machines
Simple machines make work easier and have few or no moving parts.
Wheel and Axle
A wheel and axle is a simple machine that can move objects across a distance. The wheel is the round part. The axle is a rod that goes through the centre of a wheel to help it move. A car has wheels and axles to help move.
Wheels, Axles, and Pulleys
Wheels move people and things. A wheel can be attached to a rod called an axle. The wheel moves or spins on the axle.
A wheel and axle is a simple machine.

The wheel turns around the axle.
Wheels Around You


Wheels and axles help things move. Cars, trucks, and bicycles all have wheels and axles. The axles turn the wheels.

A doorknob is a wheel and axle. You turn the wheel (the doorknob). This turns the axle.
Gears

Some wheels have teeth around their edges. These wheels with teeth are called gears.
As a gear turns, its teeth can make other gears turn. Gears can help move things.

You can find gears in cars, bicycles, and washing machines.
Pulleys

A pulley is a simple machine that can lift and lower or move a load.

A pulley has two parts. One part is a wheel with a groove around the outside.

The other part is a rope or chain.

It is difficult to carry a heavy box up a set of stairs. A pulley can help you move the box up. It can also help you lower a box.

You can raise and lower window blinds with a pulley.

Outdoor clotheslines have pulleys at both ends.
Show What You Know!
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