Georgia Amson-Bradshaw - Forces

Published in 2020 by The Rosen Publishing Group, Inc. 29 East 21st Street, New York, NY 10010 Cataloging-in-Publication Data Names: Amson-Bradshaw, Georgia. Title: Forces / Georgia Amson-Bradshaw. Description: New York: PowerKids Press, 2020. | Series: Boom science | Includes glossary and index. Identifiers: ISBN 9781725303652 (pbk.) | ISBN 9781725303676 (library bound) | ISBN 9781725303669 (6pack) Subjects: LCSH: Force and energy--Juvenile literature.

Classification: LCC QC73.4 A56 2020 | DDC 531.6--dc23 Copyright 2020 Wayland, a division of Hachette Childrens Group Series Editor: Georgia Amson-Bradshaw Series Designer: Rocket Design (East Anglia) Ltd Picture acknowledgements: lady-luck b All illustrations on pages by Steve Evans All design elements from Shutterstock. 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. 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. CONTENTS WHAT IS A FORCE? A force is a push or a pull.AND ACTION! Forces make things happen. They make objects move, change shape, change direction, speed up, or slow down.

They even make things stay still. PUSHES AND PULLS You cant see a force, but you can see what it does. Forces push and pull things. If you hit a tennis ball with a racket, that is a pushing force. When the ball falls to the ground, it is because it is pulled by the force of . STRONG AND WEAK Some forces are very strong.

Earths gravity is a strong pulling force that keeps everything from floating off into space. Some forces are weak. If you blow gently on an object, that is a weak pushing force. HEY, WHAT AM I? What are the pushing or pulling forces being . FORCES IN ACTION Forces can be balanced or un ba lanced. MANY FORCES There is almost always more than one force acting on an object at the same time. For example, when we kick a ball into the air, we see the effect of the push.

But the kick is not the only force acting on the ball. The forces pushing and pulling on the ball are all acting with different strengths. UNBALANCED FORCES When one force is stronger than the others, the forces are unbalanced. Unbalanced forces make objects change speed, direction, or shape, such as this skier who is getting faster as they go down the slope. The gravity pulling them downwards is stronger than the between the snow and their skis. BALANCED FORCES When the forces are all equal, they cancel each other out.

The object will stay completely still. If it is already moving, it will stay moving at the same speed and without changing direction. GRAVITY Objects are pulled towards each other by gravity.THE EARTHS PULL When you drop something, it falls down. Thats because it is pulled down by Earths gravity. Gravity is a non-contact force, which means Earth and the object dont have to be touching for the effect to happen. FORCES IN SPACE Earths gravitational pull doesnt just make things fall to the ground.

It keeps the moon in , too. Without gravity, the moon would float off elsewhere in space. WOw! You have a gravitational pull, too! Although we can only really see the effect of Earths gravity, every single object is pulling on the objects around it with gravity. Its just that only huge objects such as Earth have strong enough gravity for us to see the effect. HEY, WHAT AM I? What can you see gravity acting on in this picture? Answer on . FRICTION When surfaces rub together, they create friction.RUBBING TOGETHER Unlike gravity, friction is a .

It is created when two surfaces are moving, or trying to move, across each other. Friction stops or slows the movement down. Friction stops these cars from sliding down the hill. ROUGH AND SMOOTH More friction is created between rough surfaces than smooth surfaces. Think about sliding in your socks across a shiny floor. STOP IN ORDER TO GO By stopping surfaces from sliding, friction can actually help things move! Friction is what makes the wheels on a car or wheelchair the ground as they turn. STOP IN ORDER TO GO By stopping surfaces from sliding, friction can actually help things move! Friction is what makes the wheels on a car or wheelchair the ground as they turn.

This makes the car or wheelchair move forward instead of spinning on the spot. WOW! Friction produces heat. You can even start a fire using friction by spinning a wooden stick against a wooden board, until the heat starts a fire. HIDE AND SEEK Can you spot a shoe designed to increase friction, and a shoe designed to decrease friction? Answer on .