Focusing on simple machines and how they work in,our daily lives, this fun and informative new,series introduces young readers to several basic,concepts of physics - such as work, force, gravity,and friction. Includes easy-to-do experiments,colourful photos, clear text and fun activities.,This volume explores how a pulley works, showing,through fun experiments and clear diagrams how,this simple machine can make work easier and,faster. With full-colour photos on every page.,Ages 7-9