Jennifer Swanson - Explore Forces and Motion!: With 25 Great Projects

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Copyright 2016 by Nomad Press. All rights reserved.

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CONTENTS

Introduction
Everything Moves

Chapter 1
Fantastic Forces

Chapter 2
Glorious Gravity

Chapter 3
Laws of Motion

Chapter 4
Mighty Magnetism

Chapter 5
Sink or Float

Chapter 6
Forces at Work

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If the QR code doesnt work, try searching the Internet with the Keyword Prompts to find other helpful sources.

KEYWORD PROMPTS

physics of motion

You have had a long day. School was busy. You had a test in one class and a quiz in another, and you had soccer practice in the afternoon. Time to rest! You flop down in your comfy chair with a book, ready to just not move for a while. Have you ever felt like that? Did you know that while you were sitting in that big comfy chair, you were actually still moving?

In this book, we will discuss how everything moves all the time! You, your bike, the earth, and a hockey puck that glides across the ice are all in motion . What changes this movement? A force .

WORDS To KNOW

motion: the action or process of moving or changing place or position.

force: a push or pull applied to an object.

Have you ever kicked a soccer ball? Pushed someone on a swing? Picked up a box and carried it to a table? Then you have experienced forces and motion.

What is a force? A force is simply a push or a pull. You cant see a force, but you can see the effect that a force has on an object.

Forces change the way things move. This movement is called motion. Forces and motion go together. If you push something, it moves away from you. If you pull it, the object moves toward you. When you push someone on the swing, your hands are acting as the force.

Forces still act on you when you are sitting still. Gravity and pressure from the air are pushing on you while your body is pushing back! These forces are balanced. When forces are balanced, it can seem like there is no motion.

WORDS To KNOW

gravity: a force that pushes down on objects and also pulls things together in space.

pressure: a force acting on a surface from an object or fluid. Air is considered a fluid.

Motion happens when forces are unbalanced. When you kick a soccer ball, the force comes from your foot hitting the ball. That force makes the ball move across the field.

Forces can make objects speed up, slow down, or change direction. They can even make an object sink or float. Forces and motion rule the world.

MEET A PHYSICIST!

ISAAC NEWTON

Isaac Newton (16431727) is one of the most famous and important scientists of all time. Some say he discovered gravity when an apple fell on his head. While that is probably more fiction than fact, Newton was the first scientist to explain how gravity works. Newton was an excellent mathematician, too. He used his expertise in math and science to develop the three laws of motion that rule the universe. Newtons work with forces and motion paved the way for scientists to discover how they affect every part of human life!

There are many different forces that affect motion. Have you ever wondered why you always fall down and never fall up? Gravity is the force that pulls you to the ground! Magnetism is a force that attracts, but also repels. Have you ever wondered how things float? Its a force called buoyancy. And why do we make footprints when we walk in sand or snow? Your feet are applying pressure to the ground.

WORDS TO KNOW

magnetism: the force that attracts or repels between magnets.

attract: a force that draws things closer, usually applied to a magnet.

repel: a force that pushes things away, usually applied to a magnet.

buoyancy: the force that makes something able to float in a liquid or gas.

The push and pull of every object on the planet and in space is caused by the way a force acts upon it. Forces are so important to everyday life that a scientist named Sir Isaac Newton, who lived in the seventeenth century, created three laws to describe exactly how forces and motion work.

Gravity keeps the earth and the other planets in our solar system in orbit around the sun. It also keeps the moon in orbit around the earth.

In this book, you will explore how forces and motion work on us and through us every day. Youll learn more about Newtons three laws of motion. And youll become a junior physicist as you perform hands-on experiments that show the ups and downs, pushes and pulls, and even the gravity-defying properties of forces and motion. So get ready to get moving and see forces and motion in action!

WORDS TO KNOW

orbit: the path of an object circling another object in space.

property: a quality or feature of something. The way something is.

PUSH ME PULL YOU

Since we cant see forces, the best way to learn about forces is to feel them. Try this quick activity to feel a force.

Ask a partner to help you.

Draw a line or lay a stick across the sidewalk or in the grass.

You stand on one side. Your partner stands on the other.