LESSON 3

• ISAAC NEWTON

  English mathematician, physicist, astronomer, theolog ian, and author who is widely recognized as one of the most influential scientists of all time and a key figure in the scientific revolution.
• ISAAC NEWTON

  He also wrote the book “Principia Mathematica” which he formulated the laws of motion and    universal gravitation that formed the dominant scientific viewpoint   until   it   was superseded  by  the  theory of relativity.
• 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 is the tendency of an object to resist changes in its velocity: whether in motion or motionless.
• 1st  Law – 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.
• It’s a force we sometimes cannot see – friction.
• What is this unbalanced force that acts on an object in motion?

  FRICTION
• Objects on earth, unlike the frictionless space the moon travels  through, are     under the influence of friction.
• •        There are four main types of friction:

  –       Sliding friction: ice skating

  –       Rolling friction: bowling

  –       Fluid friction (air or liquid): air or water resistance

  –       Static friction: initial friction when moving an object
• LAW OF ACCELERATION

  The net force of an object is equal to the product of its mass and acceleration, or F=ma.
• 2nd Law – force equals mass times acceleration
• If mass remains constant, doubling the acceleration, doubles the force. If force remains constant, doubling the mass, halves the acceleration.
• LAW OF INTERACTION

  According to Newton, whenever objects A and B interact  with  each  other, they  exert  forces  upon each other. When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body.
• 3rd             Law –  For       every    action   there is an equal and opposite reaction.
• Law of Interaction- There   are   two forces resulting from this  interaction  -  a force on the chair and a force on your body. These two forces are called   action   and reaction forces.