LeversBook - 1994
Levers are frequently found in nature. The body's ability to move, for example, is entirely dependent on a complex system of levers. Early humans discovered that levers tremendously magnify applied force. Children who haven't yet observed this process are fascinated by it. Numerous lever-based toys provide hours of additional exploration.
Publisher: Milwaukee : Gareth Stevens Publishing, c1994
Branch Call Number: J 621.811 Oll 05
Characteristics: 28 p. :,col. ill