NEWTON’S LAW OF MOTIONS

• Aristotelian View on Motion consists of Natural Motion and Violent Motion
• Natural Motion proceeds from the nature of an object, and is not a result of the artist's intention
• Natural Motion depends on the particular combination of elements an object contains
• Natural Motion is the tendency for the object to move by nature
• Violent Motion is produced by pushes or pulls
• Violent Motion is an imposed motion that is externally caused
• Aristotelian View: Heavier objects fall faster than lighter ones - this is somewhat true due to what we call terminal velocity
• Aristotle’s ideas were accepted as a fact for nearly 2000 years
• Galileo deduced the law of inertia or Newton’s First Law of Motion by experimenting with balls and inclined planes
• State of Motion: Change in Position & Frame of Reference
• Frame of reference acts as your reference to be able to determine if an object or more are in motion
• Newton’s First Law of Motion - Every body perseveres in its state of rest or of uniform motion in a right line, unless it is compelled to change the state by forces impressed thereon
• Newton’s First Law of Motion aka Law of Inertia (Version 2.0) states that every object continues in its state of rest or of uniform velocity in a straight line, as long as no net force acts on it
• The significance of the first law connects with the concept of inertia and validates Galileo’s claim: Force is not required to keep an object moving
• When forces are not balanced then the motion of an object can be changed
• Net force - the vector sum of all the forces acting on a body (moving or at rest)
• If net force = 0 N, it implies no change on a body’s state of motion
• Newton’s Second Law of Motion aka Law of Acceleration describes the relationship among net force acting on a body, mass (m), and acceleration (a)
• Newton’s Second Law of Motion Aka Law of Acceleration: Force = mass (m) * acceleration (a)
• Acceleration is defined as the rate of change in velocity of an object over a period of time.
• Acceleration is equal to the final velocity minus the initial velocity over the time elapsed to change velocity
• The acceleration of an object is directly proportional to the net force acting on it, and inversely proportional to its mass. The direction of the acceleration is in the direction of the net force acting on the object.
• Greater net force results to greater acceleration at constant mass
• Greater mass results to less acceleration at constant net force
• Units of Mass:

  SI System = Kilogram ( kg )

  CGS ( centimeter-gram-second ) System = Gram ( g )

  British-English = Slug
• Units of Acceleration:

  SI System = Meter per second per second ( m/s^2 )

  CGS ( centimeter-gram-second ) System = Centimeter per second per second ( cm/s^2 )

  British-English = Foot per second per second ( ft/s^2 )
• Units of Force:

  SI System = Newton ( N )

  CGS ( centimeter-gram-second ) System = Dyne ( dyne )

  British-English = Pound ( lb )
• When forces are unbalanced and there is an acceleration, there are 2 routes:

  1. The acceleration depends directly upon the “net force”
  2. The accceleration depends inversely upon the object’s mass
• Newton’s First Law of Motion describes the effect of balanced forces on objects at rest and in uniform linear motion
• Newton’s Second Law of Motion describes the effect of an unbalanced force (net force) on the state of motion of an object
• Force comes from the interactions and attractions between objects
• Newton’s Third Law of Motion is also known as the Law of Interaction
• Law of Interaction - to every action, there is always opposed equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary pairs
• Newton’s Third Law of Motion aka Law of Interaction states that for every action there is always an equal and opposite reaction
• Third Law : Whenever one object exerts a force on a second object, the second exerts an equal force in the opposite direction of the first
• Action and Reaction Forces are equal in magnitude but opposite in direction and don‘t act on the same object or body
• Bullets and Third Law:

  Action force: Bullets fired from the rifle (Force on bullet)

  Reaction force: Recoiling of the rifle (Force on gun)

  The bullet also exerts an equal force on the gun in the backward direction