LONG QUIZ (PHYSCI)

• Physics


  A universal science that embraces all the laws that pertain to physical and natural phenomena that govern matter and energy and all the factors that affect them
• The study of physics started during the ancient times when Greeks made known their views on matter, motion, and the universe
• Physics helped us to understand almost every simple to complex things that occur in our surroundings
• Geocentric model


  The view that the Earth is the center of the universe
• Ancient Greek philosophers


  • Some were largely subjective and idealistic
  • Aristotle was a careful observer of his surroundings
• Observations of the movements of the planets, stars, and other celestial objects for thousands of years led early scientists and speculators to regard the Earth as the center of the universe
• Terrestrial motion


  The motions of different objects on Earth, in the sky, in the atmosphere, and in the universe
• The Greek's three types of terrestrial motions

  • Natural motion
  • Forced motion
  • Circular motion of celestial objects
• Aristotle postulated that planets and stars were made of a fifth element called "quintessence"
• Diurnal motion


  The apparent daily motion of the sky from east to west
• Annual motion


  Events or phenomena that come annually or once a year
• Precession of equinoxes


  The gradual shift in the orientation of Earth's axis of rotation
• Hipparchus discovered the precession of the equinoxes in 147-127 B.C.
• Spherical Earth


  The concept that the Earth is a sphere, dating back to around the 6th century B.C.
• Aristotle provided physical and observational arguments supporting the idea of a spherical Earth
• Plato's problem of "saving the appearances"

  The job of a philosopher to connect reality with truth using logic without violating any known principle
• Plato observed that the planets do not move at a constant rate and moved in irregular retrograde loops
• Eudoxus' model of the universe


  • Homocentric and concentric spheres inside a sphere sharing a common center which was Earth
• Eudoxus and Aristotle's paradigm involving circles in the world view of the West continued to influence the cosmology of Western thought until the 16th century
• Models of astronomical phenomena

  • Eudoxus' model
  • Aristotle's model
  • Ptolemy's model (Ptolemaic)
  • Aristarchus' model
  • Copernicus' model (Copernican)
• Tycho Brahe observed 777 stars and several planets using only a large sextant and compass
• Tycho Brahe developed accurate tables of planetary motions
• Through Brahe's observation, Kepler discovered that planets move in ellipses, not in circles
• Tychonic model


  A model of the solar system with the Earth at the center
• Galileo built his first telescope in 1609 and began making observations of the heavenly bodies
• Galileo observed lunar craters, the four largest moons of Jupiter, sunspots, and the complete range of phases of Venus
• Galileo confirmed that the orbits of the planets were circular in shape, which was later proven wrong by Kepler
• Kepler obtained Tycho Brahe's recorded data and formulated the three laws of planetary motion
• Kepler's three laws of planetary motion

  • The planets move in elliptical orbits with the sun at one focus
  • An imaginary line from the planet to the sun sweeps equal areas in equal time intervals
  • The ratio of the squares of the periods of the planets are proportional to the cubes of their mean distances from the sun
• Aristotle suggested that a force is necessary to produce motion, and that in the absence of external force, any moving body will ultimately come to rest
• Galileo challenged Aristotle's theories concerning motion through "thought experiments"
• Galileo disproved Aristotle's theory that heavier objects will reach the surface of the Earth first in free fall
• Acceleration due to gravity (g)

  The uniform acceleration experienced by a body falling freely under the influence of gravity, with a standard value of 9.8 m/s^2
• Newton studied and developed further Galileo's work on motion, and published his Principia Mathematica in 1687
• Law of inertia


  An object at rest remains at rest or if it is in motion continues to be in motion with constant speed along a straight line unless acted upon by an external force
• Law of acceleration


  The acceleration of a body is directly proportional to the magnitude of the net force acting on it, in the same direction as the net force, and inversely proportional to the mass of the body
• Law of interaction


  When two bodies interact with one another, the forces they exert on one another are equal in magnitude and opposite in direction
• Natural Motion—Was the result of the movement of things trying to get to where they belonged
• Forced Motion- was the motion that required intervention of an outside mover