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• Motion


  The action of changing location or position
• Types of motion


  • Horizontal motion
  • Vertical motion
  • Projectile motion
• Natural motion


  Objects move and return to their natural state based on their material or composition
• Violent motion


  An object moving in a violent motion requires a push or pull to maintain horizontal motion
• Projectile motion


  Parallel to the ground until the object falls back into the ground, involving both natural and violent motion
• Galileo Galilei


  • Italian Physicist
  • Father of Modern Physics
• In the absence of resistance, objects would not fall depending on their weight, but in the time of fall
• An object in horizontal motion, if unimpeded, will continue to be in motion, and an external force is not necessary to maintain that motion
• Galileo's experiments


  1. Dropped two different weights of cannon balls in the Leaning tower of Pisa

  2. Used the inclined ramp to measure the acceleration of an object
• Speed


  The distance travelled by an object divided by the time taken to travel the distance
• A ball rolling down an inclined plane increases its speed by the same value after every second. The ball increases speed by 2 m/s every second
• Galileo Galilei's concepts


  • Laws of motion
  • Concept of inertia
  • Concept of velocity
  • Idea of force that causes motion
  • The natural state of an object is rest or uniform motion
  • Objects resist motion, Inertia
• Newton's Laws of Motion


  A set of three fundamental laws that describe the relationship between an object's motion and the forces acting upon it
• First Law of Motion

  An object at rest will remain at rest, and an object in motion will continue in motion with the same speed and in the same direction, unless acted upon by an unbalanced force. Also known as the law of inertia.
• Mass is proportional to its Inertia
• Types of inertia


  • Inertia of Rest
  • Inertia of Direction
• Force


  A push or pull, measured in Newtons (N)
• Friction


  A force that opposes motion between any surfaces that are touching
• Rough surfaces have more friction than smooth surfaces
• Friction produces heat
• Net force


  The total combination of forces acting on an object
• Balanced & unbalanced forces


  Unbalanced Force occurs when the net force is greater than zero
• Galileo's inertia


  Newton's first law of motion
• Propagation of light


  The movement or transmission of light through a medium or space
• Wave model of light

  Light is made up of waves
• Particle model of light


  Light is made up of particles
• Light is a form of electromagnetic radiation that allows us to see the world around us
• Visible light comes in different colors, each with a different wavelength
• Rene Descartes' view


  Light was a mechanical property of a luminous object and a transmitting medium
• Isaac Newton's particle theory of light


  Light is composed of particles of matter called corpuscles which are emitted in all directions from a source
• Albert Einstein's theory


  Light is made up of particles called photons
• Properties of light as a particle

  • Travels in straight lines
  • Reflection (changes direction)
  • Refraction (bends, going from one material to another)
• Wave theory of light

  Proposed by Christiaan Huygens in 1678, light is made up of waves
• Properties of light as a wave

  • Interference (waves "superpose" and pass right through each other)
  • Diffraction (waves "spill over" the edges of their obstruction)
  • Polarization (eliminating one of light's "fields")
• Light has a dual nature - it sometimes behaves like a particle and sometimes like a wave
• Properties of light as a particle

  • Travels in straight lines, producing a shadow when it hits an obstruction
• Properties of light as a wave

  • Can diffract or bend around an object
• Reflection and refraction of light

  1. Light arrives at the mirror surface as a stream of particles

  2. Light, as waves, upon impacting a mirror bounce off or reflect according to arrival angles

  3. Refracting particles of light change direction upon passing between two media

  4. Refracting light as waves, changes direction upon passing from the first medium to the second medium

  
• Types of reflection


  • Plane mirror produces specular or regular reflection
  • Convex mirror produces virtual images that are reduced and located behind mirror
  • Concave mirror produces mostly real and reduced images but can also produce virtual images depending on the location of the object
• A real image is produced when an object is located in between the focus and the reflecting surface