Gravitation Newtons Law and Its Effect on Society

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GravitationNewtons Law and Its Effect on
Society

• Authors
• John Siefert
• Tiara Walburn
• Mike McDermott
• Brian Albany
• Chris Davis

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Early Ideas

• In Ancient Greece, scholars believed in an
  Aristotelian Universe, in which everything was
  stratified and had its proper position.
• Aether (everything outside the sky)
• Fire
• Air
• Water
• Earth
• Natural Motion
• In this system, all objects fall to their normal
  place. So if a rock is lifted into the air, it
  will fall back to the ground. This is called
  Natural Motion. How quickly an object falls
  depends on its weight.

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Early Ideas

• The Greeks had many other ideas about the motion
  of steller and planetary bodies as well
• Earth is at center of the Universe, with sun and
  moon revolving around it
• Stars exist in a fixed sphere beyond the orbiting
  sun and moon
• Some stars appear to wander across the sky unlike
  the others, which they name planets

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Changing Beliefs

• Galileo, in the Dialogue concerning the Two Chief
  Systems of the World (1632), proved through
  logical argument that all past theories were
  false and void, that in fact all objects fell at
  the same rate. This was discovered by his
  experimentation of tossing various size balls off
  the leaning tower of Pisa.

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Changing Beliefs

• Keplar - Came up with three laws
• 1) Elliptical orbits
• 2) Equal-area
• 3) Law of Periods
• These influenced the discovery of gravity because
  as Newtons theory was tested, Newton used
  Keplars Laws to prove existing theories of
  gravity incorrect.

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The Breakthrough

• Newton - In 1687 wrote Principia which combined
  the thoughts of Kepler, Galileo, and his own
  thoughts and experiments to prove that gravity
  was the natural force of the interactions between
  all masses in the universe.
• Mathematically, attraction is the product of the
  two masses divided by the square of the distance,
  known as the inverse square law.

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What is Gravity?

• The natural force of the interactions between all
  masses in the universe.
• The Inverse Square Law

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Earths Gravitational Properties

• Earths Gravity
• The earth has a gravitational field
• therefore an object will fall on the earths
  surface (ignoring air resistance) at a speed of
  9.8m/s2
• Free-falling
• Equation g 9.8 m/s2

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Gravitys Impact on Society

• Gravity and Astronomy
• Newtons law of gravity accounts for a great deal
  of knowledge that we know about space.
• His laws help our understanding of
• Motion of planets in our solar system
• Mass of the sun and planets
• Interstellar distances
• Orbits of objects

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Gravity In Society And Nature

• Tides
• Moon pulls on the earths center
• High and low tides
• Escape velocity
• Speed needed to break out of an objects
  gravitational pull
• Rockets leaving earth atmosphere
• Orbital speeds
• Gravity effects the revolutions of objects
• It takes one year for the earth to orbit the sun

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Gravitys Uses In Society

• Intravenous drips or gravity fed systems
• Height differences allow gravity to put pressure
  on the liquid to run downward

• Hydroelectricity
• Uses the gravitational potential energy of water
  to generate electricity

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Gravitys Uses In Society

• Fractionation towers
• Used to manufacture some materials by separating
  the material components by using their specific
  gravity

• Grandfather clocks (pendulum clocks)
• Use gravity to keep time