E_QUEST1 When you ride a ten-speed bike, which gear requires the most effort? Why?
E_QUEST2 How does a windmill work?
E_QUEST3 How do windshield wipers work?
D_TEXTBLOCK_TEXT A wheel and axle <HL Topic=Machine.tpc>MACHINE</HL> is really a form of the <HL Topic=Lever.tpc>LEVER</HL>; it is a rotating <HL Topic=Lever.tpc>LEVER</HL>, where a large wheel is connected to a smaller wheel or shaft, called an axle. The wheel can also be a crank that turns in a circular <HL Topic=Motion.tpc>MOTION</HL>. When the wheel turns the axle, there is an increase in <HL Topic=Force.tpc>FORCE</HL>. When the axle turns the wheel, there is a decrease in <HL Topic=Force.tpc>FORCE</HL> and an increase in distance and <HL Topic=Speed.tpc>SPEED</HL>.