Law of Reflection www.assignmentpoint.com
Angle of incidence = Angle of reflection The Law of Reflection Angle of incidence = Angle of reflection In other words, light gets reflected from a surface at ____ _____ angle it hits it. The same !!! www.assignmentpoint.com
Clear vs. Diffuse Reflection Smooth, shiny surfaces have a clear reflection: Rough, dull surfaces have a diffuse reflection. Diffuse reflection is when light is scattered in different directions www.assignmentpoint.com
Using mirrors Two examples: 2) A car headlight 1) A periscope www.assignmentpoint.com
Colour White light is not a single colour; it is made up of a mixture of the seven colours of the rainbow. We can demonstrate this by splitting white light with a prism: This is how rainbows are formed: sunlight is “split up” by raindrops. www.assignmentpoint.com
The colours of the rainbow: Red Orange Yellow Green Blue Indigo Violet www.assignmentpoint.com
Adding colours White light can be split up to make separate colours. These colours can be added together again. The primary colours of light are red, blue and green: Adding blue and red makes magenta (purple) Adding blue and green makes cyan (light blue) Adding red and green makes yellow Adding all three makes white again www.assignmentpoint.com
Only red light is reflected Seeing colour The colour an object appears depends on the colours of light it reflects. For example, a red book only reflects red light: Homework White light Only red light is reflected www.assignmentpoint.com
A white hat would reflect all seven colours: A pair of purple trousers would reflect purple light (and red and blue, as purple is made up of red and blue): Purple light A white hat would reflect all seven colours: White light www.assignmentpoint.com
Using coloured light If we look at a coloured object in coloured light we see something different. For example, consider a football kit: Shirt looks red White light Shorts look blue www.assignmentpoint.com
In different colours of light this kit would look different: Red light Shirt looks red Shorts look black Shirt looks black Blue light Shorts look blue www.assignmentpoint.com
Some further examples: Object Colour of light Colour object seems to be Red socks Red Blue Black Green Blue teddy Green camel Magenta book Homework www.assignmentpoint.com
Using filters Red Filter Filters can be used to “block” out different colours of light: Red Filter Magenta Filter www.assignmentpoint.com
Investigating filters Colour of filter Colours that could be “seen” Red Green Blue Cyan Magenta Yellow www.assignmentpoint.com
Red Blue Green White Yellow Cyan Magenta www.assignmentpoint.com