Question

Describe three orders of levers giving an example of each. Draw a neat diagram showing the position of fulcrum, load and effort in each kind of lever.

Answer 1

A lever is a rigid, straight or bent bar which is capable of turning about a fixed axis. Levers are classified in different classes according to relative position of effort E, load L and
fulcrum F.
Class (I) lever:
In these types of levers, the fulcrum F is in between the effort E and the load L. Example: Seesaw, scissor, and physical balance.Class (III) Levers:
In these types of levers, the load L is in between the effort E and the fulcrum F. The effort arm is thus always longer than the load arm. Example: Nutcracker, wheelbarrow and bottle opener.

Class (III) Levers:
In these types of levers, the effort E is in between the fulcrum F and the load L, and the effort arm is always smaller than the load arm.
Example: Tongs, spade and forearm used for lifting a load.