Levers summer

Levers: Simple Machines | |
Levers are one of the basic tools that were probably used in prehistoric times. Levers were first described about 260 BC by the ancient Greekmathematician Archimedes (287-212 BC).
A lever is a simple machine that makes work easier for use; it involves moving a load around a pivot using a force. Many of our basic tools use levers,including scissors (2 class 1 levers), pliers (2 class 1 levers), hammer claws (a single class 2 lever), nut crackers (2 class 2 levers), and tongs (2 class 3 levers).

A Type 1Lever. |
A Type 2 Lever. |
A Type 3 Lever. |


A Type 1 Lever. |
In a Type 1 Lever, the pivot (fulcrum) is between the effort and the load. In an off-center type one lever(like a pliers), the load is larger than the effort, but is moved through a smaller distance.
Examples of common tools (and other items) that use a type 1 lever include:
Item |Number of Class 1 Levers Used |
see-saw | | a single class 1 lever |
hammer's claws | | a single class 1 lever |
scissors | | 2 class 1 levers |
pliers | | 2 class 1 levers|


A Type 2 Lever. |
In a Type 2 Lever, the load is between the pivot (fulcrum) and the effort.
Examples of common tools that use a type 2 lever include:
Item | Number ofClass 2 Levers Used |
stapler | | a single class 2 lever |
bottle opener | | a single class 2 lever |
wheelbarrow | | a single class 2 lever |
nail clippers | | Two class 2levers |
nut cracker | | Two class 2 levers |


A Type 3 Lever. |
In a Type 3 Lever, the effort is between the pivot (fulcrum) and the load.
Examples of common tools thatuse a type 3 lever include:
Item | Number of Class 3 Levers Used |
fishing rod | | a single class 3 lever |
tweezers | | Two class 3 levers |
tongs | | Two class 3 levers |