Newtons Second Law

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Forces in One Direction

• Newtons Second Law

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Review

• From our introduction we learned that forces are
  a push or pull in a particular direction.
• Therefore velocity is affected
• Therefore acceleration is affected
• Forces can be calculated and this is accomplished
  with Newtons Second Law.

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Newtons Second Law

• The acceleration of an object is directly
  proportional to the net force acting on the
  object, is in the direction of the net force, and
  is inversely proportional to the mass of the
  object.
• a F/m
• This can be rearranged to solve for forces.

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F ma
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Yay!

• Despite the fact that this equation is almost 500
  years old, it is still one of the most powerful
  equations we know.
• A force is a push or a pull. It may be
  gravitational, electrical/magnetic, nuclear or
  simple muscular effort.

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How do we use it?

• In honor of the man who codified it, the units
  for forces are Newtons.
• What is a newton?
• F ma
• Mass units are kg
• Acceleration units are m/s2
• Therefore Newtons are equivilent to (kg m)/s2

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Forces are Vectors
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• Circle the right answer
• The forces shown above are pushing/pulling
  forces.
• The forces shown above are working
  together/opposite forces.
• The forces are equal/not equal.
• The forces do/do not balance each other out.
• The resulting force is 1000 N to the left/1000 N
  to the right/ Zero N.