O_TEXTBLOCK_TEXT Each pulley requires a different amount of <HL Topic=Effort.tpc>EFFORT</HL> to raise the object. The number of ropes supporting the <HL Topic=Load.tpc>LOAD</HL> determines how much <HL Topic=Effort.tpc>EFFORT</HL> is required. Two ropes support the load in the single-fixed/single-movable pulley so it requires less effort than the single-fixed pulley, which has only one rope supporting the load. It may take longer to raise an object with the single-fixed/single-movable pulley since the rope travels over more distance.
E_QUEST1 How does an elevator work?
E_QUEST2 How does a crane work?
E_QUEST3 How can a bale of hay be lifted to the hay loft of a barn?
D_TEXTBLOCK_TEXT A pulley is a simple <HL Topic=Machine.tpc>MACHINE</HL>. It is a type of <HL Topic=Lever.tpc>LEVER</HL> that is a wheel with a groove in its rim. The wheel is used to change the direction of a <HL Topic=Force.tpc>FORCE</HL>. A pulley or system of pulleys can also be used to multiply <HL Topic=Force.tpc>FORCES</HL>, making it possible to lift or pull objects more easily.