Levers lessen the load
(Book)

"A lever is one of six simple machines that are designed to make different kinds of work easier. Lifting, pulling, pushing--all these tasks are more efficient when you use a simple machine. In Levers Lessen the Load: Simple Machines for Kids, readers learn how levers and fulcrums can help us move far more weight than we can on our own. Need to lift a heavy rock? Use a lever! Need to push a log out of the way? Use a lever! Know where else you can find levers? In your own body--when you lift an object and carry it in your hand, you are using your arm as a lever. Concepts including forces, mechanical advantage, and different classes of levers come clear with engaging illustrations and lots of real-life examples that kids can spot in their home, schools, and neighborhoods. An introductory poem offers language arts connections while a hands-on activity at the end reinforces concepts in the book. A glossary and photographs offer even more supplemental learning opportunities."--,Adapted from publisher's website.