" You push a swing. Your brother pulls a wagon. Forces are at work all around you. But what exactly is a force? And how do forces act on different objects? Read this book to find out! Learn all about matter, energy, and forces in the Exploring Physical Science series--part of the Lightning Bolt Books(tm) collection. With high-energy designs, exciting photos, and fun text, Lightning Bolt Books(tm) bring nonfiction topics to life! "