Motion And Forces SC-05-1.2.1

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Motion And ForcesSC-05-1.2.1 SC-06-1.2.1

• May the force be with you!

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Mass vs. Weight

• Mass is the amount of stuff in an object, or
  the measure of inertia of an object.
• Weight is the pull of gravity on an object.
• An objects mass is the same throughout the
  Universe, but your weight changes depending on
  what planet your on.
• Because the gravitational pull on Mars is less
  than Earth, you weigh less on Mars, but your mass
  is the same at both locations.

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Motion

• Motion is the change in position of an object,
  measured by distance and time.

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Force

• A force is any push or pull on an object.
• Forces give energy to objects.
• Forces cause a change in the motion of an object.

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Frame of reference

• The point from which movement is determined.
• To measure movement, some point must be
  considered as nonmoving.
• Earth is the most common frame of reference.

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Speed

• The distance traveled by a moving object per unit
  of time.
• To calculate speed, use the equation
• Speed distance/time
• - Speed only gives distance and time.

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Average Speed

• The speed of a moving object is not always
  constant
• Average speed total distance/total time

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Velocity

• Velocity is the speed of an object in a given
  direction.
• Velocity gives distance, time and the direction
  of travel.

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Acceleration

• Is the change of speed over time.
• Deceleration occurs when the change in speed, or
  acceleration, is in the negative direction.
• Commonly used to mean a decrease in speed.

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Sir Isaac Newton

• An English mathematician and physicist who
  discovered one of the most important
  relationships in physics the relationship
  between the force on an object, its mass, and its
  acceleration.

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Newtons First Law of Motion

• An object will stay at rest, while an object in
  motion will stay in motion, unless acted upon by
  an unbalanced force.
• In other words, unless you apply a force to an
  object, it tends to keep doing what it was doing
  in the first place.

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Inertia

• Newton was the first to use the term inertia to
  describe the tendency of object to remain in
  motion or stay at rest. Inertia comes from the
  Latin word iners, which means lazy.

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Newtons Second Law of Motion

• The acceleration of an object is directly related
  to the force acting on it and inversely related
  to the objects mass.
• Force mass x acceleration
• In other words, force causes an object to
  accelerate, while the objects mass resists
  acceleration.

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Newtons Third Law of Motion

• For every action, there is an equal but opposite
  reaction.
• In other words, all forces act in pairs

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Friction

• Friction is a force that opposes motion.
• Friction always works against the motion that
  produces them.
• There are 3 types of friction
• Fluid Friction
• Sliding Friction
• Rolling Friction