Levers

Readers learn how this simple machine makes it easier to lift, lower, and open things. They learn the three types of levers: first-class, second-class, and third-class. By the end of the book, readers know the difference between complex and simple machines and how levers are used in everyday life to make work easier. How can we lift and lower things? How can we move heavy loads from one place to another? By using simple machines! Wheels, wedges, levers, pulleys, screws, and inclined planes are the simple machines that help us do work. In this series, students will discover how to use them each day to make life easier. Additional features to aid comprehension include a table of contents, a phonetic glossary, informative sidebars, sources for further research, an index, and an introduction to the author.