patrick

• Natural motion

  Any motion that an object does naturally without being forced
• Violent motion


  Any motion that required a force
• According to Aristotle, motion is classified as natural or violent motion
• In natural motion, a body will move and will return to its natural state based on the body's nature and composition
• In contrast, a body moving in a violent motion needs an external force for it to move
• Galilean conceptions

  • Galileo disproved Aristotle's claims
  • Galileo stated that the motion of a body is not due to its composition
  • Galileo asserted that the motion of a body can be described by measurement and the changes in quantifiable variables such as time and distance
• Galileo's assertions


  1. A body who is in uniform motion will move a distance that is proportional to the time it will take to travel

  2. A uniformly accelerating body will travel at a speed proportional to time

  3. An object in motion will keep moving; and the external force is not necessary to maintain the motion
• Galileo's cannonball experiment


  • Proved that when objects are dropped simultaneously at the same height, they will reach the ground at the same time regardless of mass, size, and air resistance
  • Paved the way for the discovery of the principle of uniform acceleration
• Acceleration


  The change in speed of a falling object
• Galileo's observations led to the conclusion that regardless of the mass, size, and shape of an object, and air resistance, falling objects will always have uniform acceleration and that, force is not necessary to sustain the horizontal motion of a body
• Galileo's law (mass independence of the acceleration of the small falling body m) is valid for the inertial observer A and presents an approximation for the ground observer B
• Galileo's inclined plane experiment and cannonball experiment


  1. A body moving down an inclined plane increases its acceleration by the same value after every second

  2. The maximum acceleration of a body is attained when the inclined plane is positioned vertically as if the body is falling

  3. Using the law of parabolic fall, he concluded that bodies fall with constant acceleration on the surface and that gravity pulling all bodies downward is a constant force

  4. Force is not necessary to sustain horizontal motion
• Inertia


  A property of matter that resists changes in motion
• Newton's first law (law of inertia)


  • If a body is at rest or in motion, it will remain at rest or keep in motion unless an external force is acted upon
• Newton's second law (law of force and acceleration)


  • The change in momentum of a body is equal to the magnitude and direction of force acting upon it
  • Force is the product of the mass of an object and its acceleration
• Newton's third law (law of interaction)


  • When two bodies interact, both will apply equal amount of forces to one another in the opposite direction
  • A force cannot be applied to an object unless something resists the reaction of that force
• The jumping force of the human on the boat will tend to push the boat backwards; the equal and opposite force of the boat on the human will propel that person towards the dock, but since the boat moves backwards, the person may end up wet
• The same problem exists for large sailboats, except with larger boat inertia, it is less noticeable
• Cosmology


  The study of the origin, evolution, and fate of the universe
• Democritus


  Held that all matter is consisted of tiny particles that were so small that they could not be broken down into any smaller pieces. Coined the word 'atomos' which literally means invisible.
• Democritus's view of atoms


  • Atoms of water were smooth because water flowed and had no discernible shape
  • Atoms of fire were thorny which is why the fire gave you painful burns
  • Atoms of earth were rough and jagged so that they stuck together to form hard materials
• Empedocles


  Combined the ideas of Thales, Anaximenes, and Heraclitus, and added the element of Earth. Thus, was born the notion of all matter being made out of differing amounts of fire, air, earth and water.
• Aristotle


  Founded the famous school of philosophy in Athens called Lyceum, perpetuated Empedocles' view of matter right through to medieval times. Entirely rejected Democritus's idea of the atom.
• Aristotelian physics pertains to the terrestrial realm. About 400 B.C. he definitively established the four classical elements of fire, air, earth and water, which were acted on by two forces, gravity and levity.
• Aristotle later added a fifth element, ether, to describe the void that fills the universe above the terrestrial sphere.
• Natural motion of earthly objects

  1. Straight lines toward center of Earth

  2. Bodies in motion naturally tend to come to rest

  3. Applied force causes deviation from natural motion

  4. Continuous application of force is needed to sustain any motion other than natural motion
• Types of terrestrial motion


  • Motion with respect to quality
  • Motion with respect to quantity
  • Motion with respect to place
• Celestial motion


  Perpetual, no reason for these motions to happen, the constant motion of celestial objects is natural
• Diurnal motion


  The apparent daily motion of stars and other celestial bodies around the Earth, caused by the Earth's rotation on its axis
• Annual motion


  The apparent motion which is a reflection of the Earth's annual orbit around the Sun
• Precession of the Equinoxes


  A cyclic wobbling in the orientation of Earth's axis of rotation, currently about 50.3 seconds of arc per year or 1 degree every 71.6 years, takes 25,772 years for a full precession to occur
• Precession is caused by the gravitational source of the sun and the moon, and the fact that the Earth is a spheroid and not a perfect sphere
• Evidence that the Earth is spherical


  • Traveler's tales of ships disappearing over the horizon
  • The Pole Star shifting to a higher position in the sky as one journeyed north
  • Aristotle's observations that there were stars seen in Egypt and in Cyprus which were not seen in the northerly regions
  • The Earth's shadow is always circular during a lunar eclipse
  • The Pole Star is higher in the sky even in short travels northwards
• Aristarchus and Eratosthenes actually measured the size of the Earth
• Patrick was a 5th-century Romano-British Christian missionary and bishop in Ireland.
• Legend credits St. Patrick with banishing snakes from the island of Ireland.
• patrick was born on march 17, 429 ad.
• he died on march 17, 460 or 461 ad.
• patrick was kidnapped by pirates when he was about sixteen years old
• St. Patrick's Day is celebrated on March 17th, the date of his death.