Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. (Physics only) How do colour filters work?
   • Colour filters work by absorbing certain wavelengths (and colour) and transmitting other wavelengths (and colour).
2. (Physics only) How is the colour of an opaque object determined?
   • The colour of an opaque object is determined by which wavelengths of light are more strongly reflected.
3. (Physics only) What colour is observed when all wavelengths of light are reflected equally?
   • If all wavelengths are reflected equally the object appears white.
4. (Physics only) What is the difference between a transparent and translucent object?
   • When waves are transmitted, the wave continues through the material. They are transparent because light is transmitted with very little absorption. Translucent materials transmit some light but are not completely clear.
5. (Physics only) What happens to wavelengths of light that are not reflected by an object?
   • Wavelengths that are not reflected are absorbed.
6. (Physics only) What colour is observed if all wavelengths of light are absorbed?
   • If all wavelengths are absorbed the objects appears black.
7. (Physics only) In terms of light, why does an object appears to be red and translucent?
   • An object appears red when the red wavelength of light is reflected, all other wavelengths of light are absorbed. The object appears translucent because some of the light is transmitted.
8. (Physics only) How can an orange light be produced using coloured filters?
   • An orange filter transmits orange light but absorbs all the other colours. If white light is shone on an orange filter, only the orange wavelengths will be observed by the human eye.
9. (Physics only) In terms of light, why does an object appear to be green and opaque?
   • An object appears green when the green wavelength of light is reflected, all other wavelengths of light are absorbed. The object appears opaque because none of the light is transmitted.