PHYSCI FINALS

• Physics


  The science of matter and its motion
• Physics


  • Deals with concepts of force, energy, mass, and charge
  • The goal is to understand the natural world
• Sub-branches of Physics


  • Modern Physics
  • Mechanics
  • Electromagnetism
  • Optics
  • Thermodynamics
• Modern Physics


  Deals with post-Newtonian concepts; based on Relativity and Quantum Mechanics
• Mechanics


  Deals with the motion of bodies under the action of forces
• Electromagnetism


  Deals with the study of electromagnetic force
• Optics


  Deals with behavior and properties of light
• Thermodynamics


  Deals with heat and temperature and its relation to energy, work, radiation, and properties of matter
• Models of the Universe

  • Geocentric Model
  • Heliocentric Model
• Geocentric Model


  • The earth-centered model of the universe
  • Pythagoras believed stars, planets, sun, and moon were attached in Crystalline Spheres
  • Eudoxus believed the whole universe revolves around the earth in spheres
  • Aristotle believed planets and stars move in perfect circles
  • Claudius Ptolemy believed planets travel in a small circular path (epicycle), as they travel around the earth (deferent)
  • Tycho Brahe believed planets revolved around the sun, and the sun and moon revolve around the earth
• Heliocentric Model


  • The sun-centered model of the universe
  • Aristarchus was the first person to propose that the sun is the center of the universe
  • Nicholaus Copernicus believed the sun is the center of the universe and the planets revolve around the sun
• Motion


  The movement of an object from one position to another with time
• Ancient Greek categories of Motion

  • Terrestrial (motion of objects in the earth)
  • Celestial (motion of objects beyond the earth)
• Motion is due to nature (living or non-living) or due to push or pull
• Using the shadow of the earth on the moon during lunar eclipse, Aristotle was able to deduce that the earth is spherical
• Galileo Galilei's experiments on Terrestrial Motion


  • Dropped 2 objects of various weights from the top of the Leaning Tower of Pisa and they hit the ground at the same time
  • Conducted experiments on slopes - downward slope increased speed, upward slope decreased speed, flat surface had no change in speed
• Friction


  Opposing motion that causes a moving object to stop
• Inertia


  Property of an object to resist change in motion
• Diurnal Motion


  Apparent movement of the sky from east to west
• Annual Motion


  Phenomena happening once a year like the changing of seasons and equinoxes
• Physical Quantities


  Properties of material or system that can be quantified by measurement
• Types of Physical Quantities

  • Scalar Quantity (described with numerical values or magnitude ONLY)
  • Vector Quantity (described with numerical values or magnitude and direction)
• Distance


  Total length of the path traveled (SCALAR)
• Displacement


  Straight line path from starting to ending point (VECTOR)
• Speed


  Distance covered per unit time
• Velocity


  Speed and direction of the motion
• Acceleration


  Change in velocity of an object due to change of speed, direction, or both
• Kinematics


  Equations that define the motion of objects without reference to forces
• Types of Kinematics


  • Linear Horizontal (motion on x-axis)
  • Linear Vertical (motion on y-axis)
• Free-falling Motion


  An object falling free from all restraints, no friction or air resistance, only acting under the influence of gravity
• All objects are falling at the same acceleration due to gravity (g=9.8 m/s2)
• Elapsed time


  The time that passed since the beginning of motion
• Characteristics of a dropped object

  • Velocity - increasing
  • Initial Velocity (Vo) = 0 m/s (initially at rest)
  • Acceleration due to gravity = + 9.8 m/s²
• Characteristics of an object thrown upward

  • Velocity - decreasing
  • Final Velocity (Vf)= 0 m/s (at the highest point)
  • Acceleration due to gravity = - 9.8 m/s²
• Isaac Newton


  English physicist and mathematician who formulated the three laws of motion
• Newton's 1st Law of Motion

  • Every object continuous in a state of rest or uniform motion unless acted by an unbalanced force
  • Also known as Law of Inertia
  • All objects have inertia
  • The mass of an object is equal to its inertia
  • More mass, more inertia
  • Moving objects don't keep in motion because there's an unbalanced force (friction, gravity, etc.)
• Newton's 2nd Law of Motion

  • The acceleration of an object is directly proportional to the net force acting on an object, is in the direction of the net force, and is inversely proportional to the mass of the object
  • Also known as Law of Acceleration
  • Mass - quantity or amount of matter in an object
  • Weight - force acted on an object due to gravity
  • Force - the product of mass and acceleration
  • The push or pull of objects
  • Formula: F = ma (a=9.8 m/s2)
  • An object will only accelerate if there is a presence of unbalanced force
  • Acceleration is directly proportional to net force and inversely proportional to mass
• Newton's 3rd Law of Motion

  • To every action, there is always an opposed equal reaction
  • Also known as Law of Action and Reaction
  • There is always a balanced force action (same magnitude, opposite direction)
  • The forces are occurring simultaneously
• Force


  Interaction between two bodies or a body and its environment
• Types of Force


  • Contact force (involve direct contact between 2 bodies)
  • Non-contact Force (acts even if two or more bodies are separated by empty space)