AQA GCSE Seeing Coloured Objects Part 2(Physics)
Seeing Coloured Objects
Before you attempt this section, make sure you review these pages first!
You will need to understand the ideas of white light containing multiple colours along with how primary and secondary colours are formed.
What colour does a red ball appear in green light?
Red is a primary colour of light.
When green shines onto the red ball. The red ball will absorb all of the wavelengths of the green light.
The red ball can only reflect wavelengths of light due to red, which there are none. So, the ball appears black.
What colour does a magenta ball appear in red light?
Magenta is a secondary colour of light, it is made up of red and blue light.
When red light shines onto the magneta ball it will reflect wavelengths that correspond to red light, so the ball will appear to be red.
What colour does a magenta ball appear to be in green light?
Magenta is a secondary colour of light, it is made up of red and blue light.
When green light shines onto the magneta ball it will absorb all of the green light.
There are no wavelengths due to red in the green light so the ball will appear to be black.
Primary colours of light and object summary table
The purpose of the table below, is not for you to learn the table as this is too difficult, but to use the information above to work out the colours that are seen or not seen.
The table below, is just a reference table to help your understanding.
| Colour of object | Colour of light shining onto the object | Wavelengths of light that the object absorbs | Wavelengths of light that the object reflects |
|---|---|---|---|
| Red | Red | None | Red |
| Red | Green | Green | None(appears black) |
| Red | Blue | Blue | None(appears black) |
| Green | Red | Red | None(appears black) |
| Green | Green | None | Green |
| Green | Blue | Blue | None(appears black) |
| Blue | Red | Red | None(appears black) |
| Blue | Green | Green | None(appears black) |
| Blue | Blue | None | Blue |
Secondary colours of light and object table
The purpose of the table below, is not for you to learn the table as this is too difficult, but to use the information above to work out the colours that are seen or not seen.
The table below, is just a reference table to help your understanding.
| Colour of Object | Colour of light shining onto the object | Wavelengths of light that the object absorbs | Wavelengths of light that the object reflects |
|---|---|---|---|
| Magenta (red and blue) | Magenta (red and blue) | None | Magenta (red and blue) |
| Magenta (red and blue) | Cyan(blue and green) | Green | Blue |
| Magenta (red and blue) | Yellow(red and green) | Green | Red |
| Magenta (red and blue) | Red | None | Red |
| Magenta (red and blue) | Blue | None | Blue |
| Magenta (red and blue) | Green | Green | None(appears black) |
| Cyan(blue and green) | Magenta (red and blue) | Red | Blue |
| Cyan(blue and green) | Cyan(blue and green) | None | Cyan(blue and green) |
| Cyan(blue and green) | Yellow(red and green) | Red | Green |
| Cyan(blue and green) | Red | Red | None(appears black) |
| Cyan(blue and green) | Blue | None | Blue |
| Cyan(blue and green) | Green | None | Green |
| Yellow(red and green) | Magenta (red and blue) | Blue | Red |
| Yellow(red and green) | Cyan(blue and green) | Blue | Green |
| Yellow(red and green) | Yellow(red and green) | None | Yellow(red and green) |
| Yellow(red and green) | Red | None | Red |
| Yellow(red and green) | Blue | Blue | None(appears black) |
| Yellow(red and green) | Green | None | Green |
Practice Question
1.Yellow light is shone onto a red jumper. State what colour the jumper would appear to be
2. Explain your answer to question 1
3. A red beam of light is shone onto a cyan dress. Describe the appearance of the dress.
Absorption and Emission of EM Radiation
JJ Thomson and Plum pudding model
Ernest Rutherford and the Nuclear Model
Niels Bohr changing the Nuclear Model
Discovering the Proton and Neutron
Measuring radiation from radioactivity
Radiation types and properties
Random nature of radioactive decay
Radioactive contamination or irradiation
Hazards of contamination and irradiation
Studies on the effects of radiation on humans
Different half lives of radioactive isotopes
Nuclear Fission Chain Reaction
Writing nuclear fission equations
Drawing ray diagrams for a concave lens
Drawing Ray Diagram to produce a virtual image for a convex lens
Drawing ray diagram to produce a real image for a convex lens.
Specular and Diffuse Reflection
Seeing Coloured Objects Part 2
Viewing objects through coloured filters
Transparent, Translucent and Opaque
Accordion Content
Accordion Content