Simple Machines challenge 2

Today Room 9 had their second challenge. This time they had to lift a stack of books with their little finger.

Which simple machine is best? After deliberating between a pulley or a lever, Room 9 decided on a lever.

Room 9 tried out various levers that happened to be in the class (Mr Wong's martial arts training sticks).

Room 9 already know that using a lever they can lift heavy objects (loads) with less effort. Now they are finding out about what happens with different length levers, or placing the fulcrum in a different place. What will they learn?

Mr Wong