Physics

• speed of light

  3.00x10^8
• specular/angular reflection


  smooth surface
• diffuse reflection


  rough surface
• from less dense to denser material

  • greater index of refraction
  • decrease wave speed
  • shorter wavelength
  • angle of reflection is less than angle of incidence
  • towards normal
• from denser to less dense material

  • less index of refraction
  • increase wave speed
  • longer wavelength
  • angle of reflection is greater than angle of incidence
  • away normal
• greater angle of refraction, slower speed
• medium to vacuum

  away normal
• vacuum to medium

  towards normal
• total internal reflection

  • more dense to less dense
  • angle is greater than critical angle
• index of refraction decreases when wavelength increases
• longer wavelength, faster speed
• concave mirror

  • converging
  • bulges away the light
  • positive f
• convex mirror

  • diverging
  • bulges towards the light
  • negative f
• concave lense

  diverging
• convex lense

  converging
• diffraction


  tendency of a wave emitted from a finitw source or passing through a finite aperture to open up because it propagates
• diffraction of light is commonly defined as the bending of light around the corners such that it spreads out and illuminates areas where a shadow is expected
• wide gap

  small diffraction effect
• narrow gap

  large diffraction effect
• polarization


  characteristic of all transverse waves
• intensity of polarized light passing through a polarizing filter

  $I•cos^2$
• passing a light through a polarizer cuts out half the light
• frame of reference


  basis coordinates
• inertial frame of reference

  It is the reference where the first law of newton is valid
• law of inertia


  an object at rest or in motion will stay that way, unless acted upon by a net external force or an unbalanced force
• special theory of relativity

  • explanation of how speed affects mass, time, and space
  • mostly used when discussing huge energies, ultra-fast speeds and astronomical distances, all without the complications of gravity
• Postulates under Special Theory of Relativity

  • The Relativity Postulate - law of physics are the same for observers in all inertial
  • The Speed of Light Postulate - the speed of light in vacuum has the same value in all directions
• Time Dilation

  • time moves differently for different observers in the same inertial frame
  • caused by gravity or velocity
• Lorentz Factor


  determines how much a system deviates from its predicted classical behavior under reletivistic conditions
• Dilated Time


  time measured by an observer in the other reference frame who sees an event in a moving frame
• Length Contraction

  • occurs when a moving object's observed length is shorter than ita propwr length
  • consequence of Eintein's theory of relativity
• Relativistic Addition of Velocities

  • used to refer to velocities where special relativity is significant
  • it takes into account effects of time dilation and length contraction, ensuring that the speed of light remains constant in all inertial reference frames
• Mass and Energy


  describes the energy of a particle at rest
• Photoelectric Effects

  • electron emission of metal surface due to light illumination
  • this is due to the transfer of energy from absorbed photons to the electrons present in metals
• quanta


  individual packets of energy that make up light
• photon


  a partivle or a packet of light
• threshold frequency


  frequency associated with incident EM radiation
• intensity of light

  • increases number of electrons
• frequency of light

  • increase of light energy
  • increase rate of electron ejection
  • increase the number of electrons ejected
• photoelectric effect

  • electron emission of metal surface due to light illumination
  • this is due to the transfer of energy from absorbed photons to the electrons present in metals