Mechanical advantage/disadvantage

• A mechanical advantage is when a lever allows you to move a large load with a smaller effort. This is because the effort arm is longer than the resistance arm
• A mechanical disadvantage is where a larger effort is needed to move a smaller load. This is because the resistance arm is longer than the effort arm
• The resistance arm is the part of the lever between the fulcrum and the load
• The effort arm is the part of the lever between the fulcrum and the effort
• The longer the resistance arm of the lever, the greater the speed at the end of it
• 1st class lever:

  • mechanical advantage + mechanical disadvantage
  • because the effort arm and resistance arm are the same length
• 2nd class lever:

  • mechanical advantage
  • because the effort arm is longer than the resistance arm
• 3rd class lever:

  • mechanical disadvantage
  • because the resistance arm is longer than the effort arm