Forces and their effects

• SI unit of force

  Newton (N)
• A device that turns when a force is exerted is called a lever
• Ways in which a force may change the motion of an object


  • Start an object moving
  • Stop a moving object
  • Change the speed of a moving object
  • Change the direction of a moving object
  • Change the size and shape of an object
• Effects of forces

  • Forces can start an object moving
  • Stop a moving object
  • Change the speed of a moving object
  • Change the direction of a moving object
  • Change the size and shape of an object x volume
  • Bring about turning effects in objects
• The point about which the lever turns is called a fulcrum (or pivot)
• How to measure a force

  1. Forces are measured with force-meters (newton meters), such as spring balances

  2. There are two types of spring balances: extension spring balances and compression spring balances