Physics
Answer
The fulcrum F and the load L are at the two ends of the lever and the effort E is somewhere in between the fulcrum F and the load L.
The effort and the load are on the same side of fulcrum but in opposite directions and the effort arm is always smaller than the load arm. Therefore, the mechanical advantage of class III lever is always less than 1.
Related Questions
The diagram below shows a rod lifting a stone.
(a) Mark position of fulcrum F and draw arrows to show the directions of load L and effort E.
(b) What class of lever is the rod?
(c) Give one more example of the same class of lever stated in part (b).
State the kind of lever which always has the mechanical advantage less than 1. Draw a labelled diagram of such a lever.
Classes III levers have mechanical advantage less than 1. Why are they then used?
State the class of levers and the relative positions of load (L), effort (E) and fulcrum (F) in
(a) a bottle opener, and
(b) sugar tongs.