Quick Notes

Quick Notes

Science Chapter 10: Machines
10.1 Lever
 

A machine is a tool used to facilitate work. This machine acts as a device that uses power to apply forces and control movement to perform an action. There are various types of machines ranging from simple machines and complex machines.
 
10.1  Lever
 
  • A lever is used to lift or pry out an object.
  • The lever consists of three parts, namely
  1. Load, which is the weight of a body
  2. Fulcrum, which is a point on a bar or object that serves as a balancer or support.
  3. Force, which is the repulsion and attraction force on an object that gives an effect.
 
Lever application

  1. The lid of the can acts as a load.
  2. The tip of the screwdriver that touches the can lid is the fulcrum
  3. The hand that pushes the screwdriver downwards acts as a force

 
Relationship between load, fulcrum and force
  • The position of the fulcrum from the load affects the force required to lift the object.
  • To lift a heavy load, we need:
  1. Place the fulcrum closest to the load
  2. The force is applied as far as possible from the fulcrum
  3. Use long sticks, not short sticks. 

  • The closer the load distance from the fulcrum, the lesser the force is needed to lift the load.
  • The farther the load distance from the fulcrum, the more force is needed to lift the load.