Turn trash into invention and sharpen your engineering eye with these 10 hands-on engineering projects. Using recycled and easy-to-find materials, engineer your own motorcar, catapult, glider, and other completely functional machines. Explore amazing scientific concepts, such as potential, kinetic, and electrical energy; principles of flight; weights and balances; pulleys and levers; laws of motion; and more. Each project includes step-by-step instructions, full-color photos, exciting facts, safety tips, and extended engineering and science activities for further discovery.