Readers learn all about pulleys—the simple machines that help lift heavy objects. Pulleys are also used to change the direction of a pulling motion. If you’ve sent a flag up a flagpole, you’ve used a pulley. The science behind pulleys is explained through accessible text, including a helpful glossary of important terms. Vibrant photographs allow readers to see firsthand how these simple machines work, and a graphic organizer provides important facts in an eye-catching way. This book presents essential science concepts through creative methods, engaging readers.