Gravity

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Gravity
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Gravity

• Gravity? is the force of attraction between
  objects that have mass.
• The strength of gravity between tow objects
  depends on two things
• The mass of the object
• Distance between the two objects

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Mass

• Remember Mass is the amount of stuff in an object
• The greater the mass of either object, the
  stronger the gravity between them
• Example The force of gravity between you and the
  earth is stronger than you and an apple. Why?

4
Distance

• Distance between two objects? The closer together
  the objects are the stronger the gravitational
  force.
• Farther apart the objects are the weaker the
  force.
• Everything on or anywhere near the earth is
  pulled toward the Earths center by a
  gravitational force.

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Weight

• Weight
• F ma m x (9.81 m/s2 )
• Weight of the object is also the gravitational
  force.
• Your weight is the gravitational force between
  you and earth.
• Your weight would be different on other planets.

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Moon

• Tides? Changes in ocean water levels that take
  place in a regular pattern.
• Tides are controlled mostly by the pull of
  gravity between the moon and earth
• The force of gravity due to the moon pulls ocean
  water away from the Earths surface.

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Earth and Moon

• As the Earth rotates, water is pulled up onto the
  shore at parts of the earth that face directly
  toward or away from the moon? High tide
• At the same point ocean water pulled away from
  the shorelines of points on Earth that are not
  pulled by the moon at that moment? low tide

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Solar System

• The solar system includes the sun and all objects
  in space that are affected by the suns gravity.
• Suns diameter is 1,390,180 kilometers
• All the planets revolve around the sun.
• The planets stay in orbit because of the
  gravitational force between each planet and the
  sun

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Summary

• Summary
• Every object exerts a gravitational force on
  every other object and that force depends on how
  much mass the objects have and how far apart they
  are.