newtons laws

• Newton's 1st law

  An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force. It can also be called the law of inertia.
• Examples of Newton's 1st law

  • A ball rolling down a hill will continue to roll unless friction or another force stops it
  • The use of brakes to slow down
  • An electric fan continues to move for a period of time after the electricity is turned off
  • A bicycle moving at constant velocity would maintain this velocity without the application of force
• Inertia

  An object remains at rest or in constant motion in a straight line unless acted on by a net unbalanced force. The greater the mass of an object, the larger the mass. Inertia is a property of an object that describes how much it will resist change to the motion of an object. More mass = more inertia.
• Main types of friction


  • Sliding friction (ice skating)
  • Rolling friction (bowling)
  • Fluid friction (air or water resistance)
  • Static friction (initial friction when moving an object)
• Newton's 2nd law

  An object acted on by an unbalanced force will accelerate in the direction of that force, in direction proportion to the strength of the force, and in inverse proportion to the mass of the object. Sometimes it's called the law of force and motion or law of acceleration.
• Newton's 3rd law


  For every action there is an equal and opposite reaction. Whenever an object A applies a force (action) to another object (B), B will apply an equal and opposite force (reaction) to A. The main idea is that the two forces are applied to different objects.