Light Sound and Waves

Light meeting obstacles

Physics Narrative for 5-11 11-14 Supporting Physics Teaching

Three possibilities

What happens when light travels through the air and meets the surface of an object, such as a table, mirror, window, or curtain? Various outcomes are possible.

Notice that all of the energy of the incident beam can only be shared out amongst the three possibilities: energy is conserved.

If the object is:

  • Opaque: no light is transmitted (the light is reflected and absorbed to varying degrees).
  • Translucent: some light is transmitted (the rest of the light is reflected and absorbed to varying degrees).
  • Transparent: ideally all light is transmitted (although in practice some light will be reflected and absorbed).

Notice that all the energy must be accounted for – energy is conserved.

is formalised by Law of Reflection
can be exhibited by Progressive Wave
has the special case Total Internal Reflection
IOP DOMAINS Physics CPD programme

Waves CPD videos

Our new set of videos gives teachers and coaches of physics a preview of the training we offer ahead of this term's live support sessions.

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