Physical Science by Ann J. Jacobs Genre Nonfiction Comprehension Skill Summarize Text Features Captions Chart Glossary Science Content Forces in Motion Scott Foresman Science 3.12 ISBN 0-328-13841-X ì<(sk$m)=bdiebi< +^-Ä-U-Ä-U Vocabulary What did you learn? force 1. What is the difference between constant speed Ann J. Jacobs and variable by speed? friction gravity magnetism motion Forces and Motion 2. Would it take more force to begin moving an empty wagon or a wagon loaded with pumpkins? Why? position 3. What is the difference between a contact force and a non-contact force? Give examples of each. relative position 4. In this book you have read about work and simple machines. Write to explain how simple machines make work easier without lessening the amount of work that gets done. Use examples from the book. 5. Summarize Turn to p. 11. Summarize the forces used when riding a bike. speed work Photographs: Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Unless otherwise acknowledged, all photographs are the property of Scott Foresman, a division of Pearson Education. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R) Background (Bkgd) Opener: ©Allsport Photography/Getty Images; 2 ©David Young-Wolff/PhotoEdit; 4 ©Roy Ooms/ Masterfile Corporation; 5 ©John Elk/Bruce Coleman Inc.; 6 (TL) ©Richard Megna/Fundamental Photographs, (CR) ©Stone/Getty Images, (BL) ©Tom Szuba/Masterfile Corporation; 7 ©Kunst & Scheidulin/Age Fotostock; 8 ©Jim Cummins/Corbis; 10 ©Rolf Bruderer/Corbis; 11 ©Stone/Getty Images; 12 ©Hennie Wiggers/Zefa/Masterfile Corporation; 14 ©Taxi/Getty Images; 15 AlaskaStock; 16 ©Bob Daemmrich/Corbis; 17 ©DK Images; 18 (CL) Getty Images, (R) ©Tony Freeman/PhotoEdit; 20 Corbis; 22 ©Keith Pritchard/Alamy Images; 23 ©Nei