Law of Inertia

• Law of Inertia


  Newton's first law of motion
• Law of Inertia


  • An object at rest will stay at rest, and an object in motion will stay in motion at constant velocity, unless acted upon by an unbalanced force
• Inertia


  The resistance of an object to a change in its state of rest or uniform motion
• Uniform motion


  Motion in a straight path with no change in speed or direction
• Mass


  The measure of an object's inertia, the amount of matter present in it
• Greater mass of an object

  Greater its inertia
• Two objects of different masses resting on a surface

  The one with larger mass has greater tendency to remain at rest than the one with lesser mass
• Two moving objects of different masses

  The one with larger mass has greater resistance to any change in motion
• Forces exerted on an object

  1. May cause its motion or acceleration

  2. Ball resting on a surface will remain motionless because of its inertia

  3. If an unbalanced force is applied, the ball will start to move
• Crate moving at a constant velocity

  1. Will continue moving at that velocity because of its inertia and if no force acts on it

  2. If equal forces are applied in opposite directions (balanced forces), its velocity will remain the same

  3. If an unbalanced force is applied, its velocity will be affected, and it will accelerate
• The concept of acceleration will be discussed further in Newton's second law of motion, the law of acceleration