Studying

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Studying

• Newtons Three Laws of Motion

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Sir Isaac Newton (January 1643 March 1727)

• Newton's laws of motion are three physical laws
  which provide relationships between the forces
  acting on a body and the motion of the body.

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Newtons First Law

• An object at rest will remain at rest- unless
  acted upon by an outside force.

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Newtons First Law

•           

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Chapter 6
Newtons First Law of Motion
An object at rest remains at rest, and an object
in motion remains in motion at a constant speed
and in a straight line unless acted on by an
unbalanced force.
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Chapter 6
Newtons First Law of Motion, continued
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The First Law is Also Called

• The Law of Inertia
• Inertia is a resistance to change in motion.

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Can You Explain ?
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Examples

• An object at rest will remain at rest.

• Activity 1
• Freefall

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The Tablecloth Trick
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• An object in motion will continue to move in a
  straight line.

• For Example

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The Story of Fluffy
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Poor Baby Barbie

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Anti- Inertia Belts

• Better known as Seatbelts !

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Chapter 6
Newtons Second Law of Motion

• The acceleration of an object depends on the mass
  of the object and the amount of force applied.
• Newtons second law describes the motion of an
  object when an unbalanced force acts on the
  object.

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Newtons Second Law

• This Law shows the relationship between mass,
  force, and acceleration.
• When a force is applied to a mass, it accelerates.

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The larger the mass of an object, the more force
needed to start it, stop it, or change its
direction.
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Chapter 6
Newtons Second Law of Motion

• The acceleration of an object depends on the mass
  of the object and the amount of force applied.
• Newtons second law describes the motion of an
  object when an unbalanced force acts on the
  object.

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Chapter 6
Newtons Second Law of Motion

• Part 1 Acceleration Depends on Mass The
  acceleration of an object decreases as its mass
  increases. Its acceleration increases as its mass
  decreases.
• Part 2 Acceleration Depends on Force An
  objects acceleration increases as the force on
  the object increases. The acceleration of an
  object is always in the same direction as the
  force applied.

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Section 2 Newtons Laws of Motion
Chapter 6
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Section 2 Newtons Laws of Motion
Chapter 6
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Newtons Second Law

• For Example A Bowling Ball vs a
  ping pong ball.

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Or Runaway Ramps

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Choose Your Position..

• Some Athletes are long and lean, with little
  body fat, and little muscle. Basketball players
  and wide receivers fit this category.

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Choose Your Position

• Other athletes, on the other hand, have lots
  of body fat, lots of muscle, and gain weight
  easily. Football lineman and sumo wrestlers are
  heavier and rounder individuals

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Momentum, Mass, and Velocity

• The momentum of an object is the product of the
  objects mass and velocity. Object at rest has
  zero momentum.
• Calculating Momentum The relationship of
  momentum (p), mass (m) in kilograms, and velocity
  (v) in meters per second, is shown in the
  equation below
• p ? m x v

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What is (i) the total kinetic energy before
the collision (ii) the total kinetic energy
after the collision. (iii) the total loss in
kinetic energy.
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The Law of Conservation of Momentum

• The law of conservation of momentum states that
  any time objects collide, the total amount of
  momentum stays the same.

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The Law of Conservation of Momentum

• The combined objects have a different velocity
  because momentum is conserved and depends on mass
  and velocity.
• So, when the mass changes, the velocity must
  change, too.

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The Law of Conservation of Momentum, continued

• Objects Bouncing Off Each Other When two
  objects bounce off each other, momentum is
  transferred from one object to the other.
• The transfer of momentum causes the objects to
  move in different directions at different speeds.

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The Law of Conservation of Momentum, continued

• Conservation of Momentum and Newtons Third Law
  Conservation of momentum can be explained by
  Newtons third law.
• Because action and reaction forces are equal and
  opposite, momentum is neither gained or lost in a
  collision.

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Forces Always Come in Pairs

• .

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Newtons Third Law of Motion

• Whenever one object exerts a force on a second
  object, the second object exerts an equal and
  opposite force on the first.
• Newtons third law of motion can be simply
  stated as follows All forces act in pairs.

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Newtons Third Law

• For every action force, there is an equal, but
  opposite, reaction force.

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The Action Force is Equal in size but Opposite in
Direction.
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Action and Reaction forces always act on
different objects.

• Action Force The man pushes against the wall.
• Reaction Force the wall pushes on the man.

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Newton's third law does not mean that forces
always cancel out so that nothing can ever move.
If these two figure skaters, initially at rest,
push against each other, they will both move.
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Another example Recoil of a gun or cannon
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OrLaunching a Rocket

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Or a Lawn Sprinkler
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