An exciting book about the chain reaction world of Rube Goldberg for middle schoolers, including 25 engineering design projects that get middle schoolers applying the laws of physics to their own inventions as they learn the scientific principles behind the actions and reactions they create.

Why use a simple hand motion to wipe your mouth when you can build a machine to do it for you? Toppling dominoes, rolling marbles, racing balloon cars, springing catapults, and whizzing zip-lines are all elements used to build Rube Goldberg machines in Crazy Contraptions: Build Rube Goldberg Machines that Swoop, Spin, Stack, and Swivel with Hands-On Engineering Activities. The book introduces kids ages 9-12 (and beyond!) to the wacky machines designed by Goldberg, which were based on complicated chain reactions used to accomplish very simple, sometimes ridiculous, tasks.