Rourke’s World of Science Volume 6 PHYSICS By Nancy Harris Editorial Consultant Debbie Ankiel www rourkeeducationalmedia com
TABLE OF CONTENT S What is Physics 4 Energy 5 Mass Length and Time 5 Motion and Force 6 Motion 6 Force 6 The Four Fundamental Forces 7 Velocity and Acceleration 8 Newton’s Three Laws of Motion 10 Friction 12 Circular Motion 13 Gravity 15 Energy 17 Work 17 Simple Machines 17 Forms of Energy 23 Conservation of Energy 23 Potential and Kinetic Energy 24 Momentum and Collisions 26 Electricity and Magnetism 27 Electric Charges 27 Current 30 Magnetism 32 Heat 36 Temperature 36 Expansion and Contraction 37 How Heat Works 40 The Uses of Heat 41 Waves Sound and Light 43 Waves and Sound 43 The Nature of Light 45 Where Light Comes From 48 Reflection and Refraction 48 Nuclear Energy 52 Uses of Nuclear Energy 53 Fission and Fusion 54 People Who Study Physics 60
What Is Physics S Physics is the science of how the universe works It is a science based on experiments observation and measurement Experiments involve making things change Observation is when scientists watch what they are studying very carefully Measurement is describing things by their weight size or temperature Physics looks at how tiny atoms are put together Atoms are tiny particles that make up everything in the universe Physics looks at how huge planets and stars move It helps scientists understand the way matter acts Matter includes the solids liquids and gases in the universe Physics also helps scientists understand how energy acts C I S Y H P S I T A H W PHYSICS A physicist uses precise measurements The protons and neutrons in the nucleus of an atom are surrounded by a cloud of electrons Astrophysicists are physicists who study the stars and planets 4
