ACTION Work The most exciting ways to work and move around our planet and the science that lets us Gerry Bailey Felicia Law Illustrations by Ira Olenina
3 3 Hoist Truck Pedicab Monorail Glossary Index Credits 36 38 40 42 44 46 48 pulley hoist combustion engine wheel and axle electromagnet Machines are used to do work Work in this case describes what takes place when a force moves something To do work machines need energy The energy that machines use may be electrical energy or chemical energy from fossil fuels such as gasoline or diesel Power is the rate at which work is done It is measured in watts or horsepower Power can be as little as the power from a bicycle rider’s legs or as much as the massive power of a huge road train But all machines need energy and power Let’s look at some of the brilliant action machines that help us do different kinds of jobs and the science that makes it possible
