Springs (Machines in Action)

Springs have been used for more than 500 years as a simple machine that can make other machines work. When you open a screen door, open an umbrella, sit on a sofa, or sleep on a mattress you are using springs. This book explains what springs are and how they help you do everyday things. Topics include: Why won't a Slinky go up stairs? How can a catapult help a place take off? How does a clock work?