Explains how a pulley works and introduces the ways they are used in everyday life.

Sound and light aren't just sensations picked up by our senses--they're examples of science at work in the wonderful world around us! Budding scientists will delight in the text's age-appropriate experiments, which are made easy through step-by-step instructions and photos. Each experiment is accompanied by a question-and-answer feature that answers common questions encountered while experimenting, and a concluding quiz tests reader's knowledge of...

Describes the structure and mechanics of automobiles, including how an engine works, what components generate an easier ride, and how electric and fuel cell cars differ from those with combustible engines.

You will find the answers to over 100 intriguing questions about the U.S. presidents in this book.

Describes how skyscrapers are different from towers and how both are constructed.

Text and activities introduce wedges and ramps and explain how wedges and ramps work.

Presents facts about the planet Mars, and discusses what it would be like to take a trip there.