Ronald Machut - Working with Wheels and Axles

Published in 2020 by The Rosen Publishing Group, Inc. 29 East 21st Street, New York, NY 10010

Copyright 2020 by The Rosen Publishing Group, Inc.

All rights reserved. No part of this book may be reproduced in any form without permission in writing from the publisher, except by a reviewer.

Copyright 2011; revised edition 2020

Editor: Elizabeth Krajnik

Book Design: Reann Nye

Photo Credits: Cover, p. 10 Narudom Chaisuwon/Shutterstock.com; p. 6 feelphoto2521/Shutterstock.com; p. 7 Rolf E. Staerk/Shutterstock.com; p. 9 Polo Gtz/Shutterstock.com; p. 11 Mattia Mazzucchelli/Shutterstock.com; p. 13 Westend61/Getty Images; p. 14 Cezary Wojtkowski/Shutterstock.com; p. 15 MARGRIT HIRSCH/Shutterstock.com; p. 17 biletskiy/Shutterstock.com; p. 19 dimcars/Shutterstock.com; p. 21 iMoved Studio/Shutterstock.com; p. 22 Naypong Studio/Shutterstock.com.

Cataloging-in-Publication Data

Names: Machut, Ronald.

Title: Working with wheels and axles / Ronald Machut.

Description: New York : PowerKids Press, 2020. | Series: Doing work with simple machines | Includes glossary and index.

Identifiers: ISBN 9781538345368 (pbk.) | ISBN 9781538343654 (library bound) | ISBN 9781538345375 (6pack)

Subjects: LCSH: Wheels--Juvenile literature. | Axles--Juvenile literature.

Classification: LCC TJ181.5 M33 2020 | DDC 621.8--dc23

Manufactured in the United States of America

CPSIA Compliance Information: Batch #CSPK19. For Further Information contact Rosen Publishing, New York, New York at 1-800-237-9932

WHATS A WHEEL AND AXLE?

Wheels and axles are found in many places, but you might not even know theyre there. Ferris wheels, doorknobs, and steering wheels are all examples of wheels and axles.

The wheel and axle is one of six simple machines. A simple machine is a device with few or no moving parts. These devices are used to modify, or change, motion and force to do work. Force can be applied to either the wheel or the axle. When you turn a doorknob, youre applying force to the wheel. A ceiling fan is an example of force being applied to the axle.

MECHANICAL MARVELS

Some devices are made up of more than one simple machine. Theyre called compound machines. Cars,dishwashers, and lawn mowers are all compound machines.

The other simple machines are the inclined plane, the wedge, the pulley, the screw, and the lever.

WHEEL AND AXLE PARTS

A wheel and axle is made up of two circular objects of different sizes that are joined at the center. The larger circular object is called the wheel and the smaller rod is called the axle.

MECHANICAL MARVELS

Some wheels and axles, such as a screwdriver, are powered by human effort. Others, such as cars, school buses, and trucks, are powered by engines.

Without its axle, a Ferris wheel wouldnt be able to spin. It also wouldnt be considered a simple machine.

To be considered a simple machine, the wheel and axle must be joined. A wheel that turns around an axle but isnt connected to the axle isnt a simple machine. Some wheels and axles may have a wheel on just one end of the axle. Other wheels and axles may be made up of wheels on both ends of the axle.

A SPECIAL SIMPLE MACHINE

Wheels and axles are special simple machines because they act like another simple machine. A wheel and axle is actually a kind of first-class lever. In most cases, a lever is a long plank that pivots, or turns, on or around a central point called a fulcrum.

When you apply force to the wheel, the wheel multiplies the force to make the force produced by the axle greater. When you apply force to the axle, the force makes the wheel turn a greater distance than it would with the force applied to the wheel alone. The axle multiplies the force to the wheel.

In the case of a wheel and axle, the wheel acts as one end of the lever and the axle acts as the other. The point at the center of both the wheel and the axle is the fulcrum.

DOING WORK

Wheels and axles do important work. But each part of a wheel and axle does its work in a different way. A doorknob is a wheel attached to an axle inside the door. When you apply effort to the knob, the axle turns the parts that allow the door to open.

Some cars only deliver power to either the front wheels or the back wheels. Other cars have four-wheel drive.

In the case of cars and other vehicles, force from the engine is applied to the axle. When the axle spins, it causes the cars wheels to spin. The engines power is greater than the friction of the road, which allows the car to move forward with the help of the wheels and axles.

THE EARLIEST WHEELS AND AXLES

Unlike some other simple machines, wheels dont exist in nature. The people of Mesopotamia invented the earliest wheels around 3500 BC. They used these wheels, which were made of solid stone or circles of wood cut from trees, as potters wheels.

A potters wheel is a flat, round stone or piece of wood attached to a pedal. When the potter pushes the pedal down, an axle turns, which spins the wheel. To make clay pots, a potter needed to shape clay by hand or use a potters wheel. Clay pots were very important in everyday life in ancient times. They were used to store food, water, and other things.

MECHANICAL MARVELS

Historians have said that the wheel is one of very few inventions that wasnt inspired by something in nature.

Sometime between the sixth and fourth centuries BC, people in Greece invented the wheelbarrow. This invention spread throughout the world from China to Europe.

WHEELS AND AXLES THROUGHOUT HISTORY

People have used wheels and axles to help them do work for thousands of years. Early windmills used several wheels and axles to work. The large sails of a windmill turned on an axle, powered by the wind. The axle was joined to wheels and gears within the main building.