Book excerpt: Though students aren’t yet old enough to drive, that doesn’t mean they can’t satisfy their need for speed. Author and physics teacher Bobby Mercer will show readers 25 easy-to-build racecars that can be driven both indoors and out. Better still, each of these vehicles is constructed for little or no cost using recycled and repurposed materials. The Racecar Book will teach readers how to use mousetraps, rubber bands, chemical reactions, gravity, and air pressure to power these fast-moving cars. They will learn how to turn a potato chip can, a rubber band, and weights into a Chip-Can Dancer, or retrofit a toy car with a toy plane propeller to make an air-powered Prop Car. An effervescent tablet in a small canister makes an impressive rocket engine for a Mini Pop Car, and old CDs, a small cardboard food box, and drinking straws become a Mac-n-Cheese Roller. Every hands-on project contains a materials list and detailed step-by-step instructions. Mercer also includes explanations of the science behind each racecar, including concepts such as friction, Newton’s laws of motion, kinetic and potential energy, and more. Teachers will appreciate the opportunity to augment their STEM curricula while having fun at the same time. These projects are also perfect for science fairs or design competitions. Bobby Mercer has been a high school physics teacher for over two decades. He is the author of The Flying Machine Book and Smash It! Crash It! Launch It! and lives with his family outside of Asheville, North Carolina.