Fifth Grade Science

Levers

Lever- a stiff bar that rests on a middle support

Load- the weight or the resistance that needs to be overcome

Lever- stiff bar Fulcrum-

pivot point (fixed)

Effort- the force applied to move a load

Parts of a Lever

Levers can be classified into three different types or classes.

First Class Levers

In a Class 1 lever, the fulcrum is between the effort and the load.

EFL

LFE

First Class Levers

Examples of common tools (and other items) that use a type 1 lever include:

ItemNumber 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

Second Class Levers

In Class 2 levers, the load is between the fulcrum and the effort.

ELF

FLE

Second Class LeversExamples of common tools that use a type 2 lever include:

Item Number of Class 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 2 levers

nut cracker Two class 2 levers

Third Class Levers

In Class 3 levers, the effort is between the fulcrum and the load.

LEF

FEL

Third Class Levers

Examples of common tools that use a type 3 lever include:

ItemNumber of Class 3 Levers Used

fishing rod                    a single class 3 lever

tweezers Two class 3 levers

tongs

                                  Two class 3 levers

Which Type of Lever Am I?

Class 2 Lever!!

Fulcrum Load

Effort

Class 1 Lever!!

FulcrumLoad Effort

Class 3 Lever!!

Fulcrum

Load

Effort