Based on the position of the Fulcrum (pivot), Load, and Effort, Levers are of the following three kinds.
First class Lever / Class one Lever (Load -Fulcrum – Effort )
A lever in which the fulcrum is located between the load and the effort is called class-one lever.
Examples: A pair of scissors, a seesaw, and a crowbar are examples of class-one levers.
Activity To Demonstrate- First class Lever / Class one Lever
Aim: To demonstrate a class-one lever
Materials: A pair of scissors and a piece of paper
Procedure: Hold the paper in your left hand and carefully use the scissors to cut the paper into two halves.
Observation: Effort is applied by the fingers at one end of the scissors and the paper is cut into two halves.
Conclusion: The pair of scissors is a simple machine. Effort is applied at one end of the scissors and the load (paper) is placed at the other end. The fulcrum lies in between load and effort where the two parts of the scissor are joined. So, it is a class-one lever.
Also Check – Types Of Simple Machines
Second Class Lever/ Class two Lever(Fulcrum – load– Effort )
A lever in which the load is located between the fulcrum and the effort is called class-two lever
Example: . A wheelbarrow, a bottle opener, and a nutcracker are examples of class-two lever.
Activity to Demonstrate Second Class Lever/ Class two Lever
Material: walnut and nut cracker
Procedure:
- Hold the nutcracker in your right hand and the walnut in your left hand. In the presence of an adult, place the walnut between the teeth of the nutcracker. 2. By applying force with your hand over the handle, try to crack the walnut.
Observation: The walnut may crack depending upon how much force is applied.
Conclusion: The nutcracker is a simple machine. The effort is applied by you at one end of the nutcracker over the handle. The fulcrum lies at the other end (where the upper and lower parts of the nutcracker are joined), while load (walnut) lies between the effort and the fulcrum. So, it is a class-two lever.
Third Class Lever/ Class Three Lever (Fulcrum – Effort – Load )
A lever in which the effort is located between the fulcrum and the load is called Class-three lever.
Example: A fishing rod, tweezers, and a pair of tongs
Activity To Demonstrate Third Class Lever / Class 3 Lever
Aim: To demonstrate a class-three lever
Material: A pair of tongs and a piece of sugar cube
Method: Hold the tongs in your right hand and lift the piece of sugar.
Observation: By applying force with your hand on the tongs, press upon the piece of chalk and try to lift it.
Conclusion: The fulcrum lies at one end of the tongs (where the upper and lower portion of the tongs meet) and the load is at the other open end. Here, the load is the sugar cube. You press on the middle portion of the tongs. Hence, effort is in between fulcrum and load. Thus, a pair of tongs is a class-three lever.
