Lever and Its Types
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Levers are basic tools used since prehistoric times to make work easier by amplifying force around a pivot. There are three types of levers: first-class (fulcrum between effort and load), second-class (load between effort and fulcrum, like a wheelbarrow), and third-class (effort between load and fulcrum, like a hammer). Each type has specific applications and demonstrates the principle that an input force can be transformed to achieve a greater output force.
Lever and Its Types
- 1. LEVERS AND ITS TYPES Prepared By Ronnith Nandy
- 2. - Levers are one of basic tools that were probably used in prehistoric times. It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons. Lever is a simple machine that makes work easier to use; it involves moving a load around a pivot using a minimum force. A lever amplifies an input force to provide a greater output force,which is said to provide leverage. The levers are used to lift heavy weight with least amount of effort. LEVERS
- 3. - Lever – A bar that is free to pivot around a center point (Changes direction and/or amount of force). Fulcrum – The fixed point around which a lever pivots (fulcrums can take many shapes). Effort Force – The force applied to a machine to cause motion of an object. (Measured in Newton N) Resistance Force – The force exerted by an object due to gravity or friction. (Measured in Newton N) Resistance Arm – The part of the lever on which the resistance force is exerted. Effort Arm – The part of the lever to which the effort force is applied. LEVER SYSTEM
- 4. -PRINCIPLE OF LEVER The lever is based on the principle of lever stating that: "The force pushing upward at one end of a lever is equal to the force pushing downward at the other end times the ratio of the distance of the two forces from the pivot point. The figure illustrates the principle of the lever.
- 5. -EXAMPLES OF LEVER IN EVERYDAY LIFE
- 6. - In a Class 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. FIRST CLASS LEVER
- 7. -FIRST CLASS LEVER EXAMPLE IN EVERYDAY LIFE
- 8. -SECOND-CLASS LEVERS Second-class levers have the load between the effort and the fulcrum. A wheelbarrow is a second-class lever. The wheel’s axle is the fulcrum, the handles take the effort, and the load is placed between them. The effort always travels a greater distance and is less than the load.
- 9. -SECOND CLASS LEVER EXAMPLE IN EVERYDAY LIFE
- 10. -THIRD-CLASS LEVERS Third-class levers have the effort placed between the load and the fulcrum. The effort always travels a shorter distance and must be greater than the load. A hammer acts as a third-class lever when it is used to drive in a nail: the fulcrum is the wrist, the effort is applied through the hand, and the load is the resistance of the wood.
- 11. - THIRD CLASS LEVER EXAMPLE IN EVERYDAY LIFE
- 12. - THANK YOU