What are the colours of a rainbow?

Ray diagram review WWW EBI I have labelled all rays and angles correctly I have labelled most rays and angles correctly I have drawn correct direction arrows on all my rays I have drawn the normal at 90 I have drawn diagrams with a pencil and ruler I need to make sure I label all rays and angle correctly I need to draw correct direction arrows on all the rays I need to use a pencil when drawing diagrams I need to make sure I measure all angles carefully

Dispersion Success Criteria Today you will: State what happens when light passes through a prism Explain why different colours are refracted through different angles Describe how rainbows are created

Know that light is dispersed when it shines through a prism What happens when light meets a boundary between air and glass? It refracts. glass air Why does it refract? Light travels at different speeds in different materials: – light travels more slowly in glass than air – the inside of the ray slows down before the outside - so the light bends.

Know that light is dispersed when it shines through a prism What will happens when light is shone through a prism? The light is split : it is dispersed. Dispersion: when light splits into separate colours.

Understand that different colours are refracted through different angles How does a prism split light into different colours? Copy the diagram into your book and add the labels ray box prism normal angle of incidence screen

Understand that different colours are refracted through different angles How does a prism split light into different colours? Set up the equipment as shown in your diagram Move the incident ray until you see the best spectrum on the screen – measure this angle of incidence. Record the colours you can see on the screen

Ray diagram review – part 2 WWW EBI I have labelled all rays and angles correctly I have labelled most rays and angles correctly I have drawn correct direction arrows on all my rays I have drawn the normal at 90 I have drawn diagrams with a pencil and ruler I need to make sure I label all rays and angle correctly I need to draw correct direction arrows on all the rays I need to use a pencil when drawing diagrams I need to make sure I measure all angles carefully

Understand that different colours are refracted through different angles

Richard Of York Gave Battle In Vain Understand that different colours are refracted through different angles Red Orange Yellow Green Blue Indigo Violet The colours that make up white light are called the spectrum. The order of the colours in the spectrum is always the same, because different colours are refracted by different angles. Richard Of York Gave Battle In Vain

Be able to explain how rainbows are created What conditions are needed for a rainbow to be created? How does this create a rainbow? Rain + Sun

Be able to explain how rainbows are created Your friend has sent you a postcard saying that they have seen a rainbow on holiday, but they don’t understand how this happens. Write a postcard back explaining how a rainbow is created… raindrops speed refraction/ refracted sunlight dispersion/ dispersed angle

Be able to explain how rainbows are created We see light from the Sun as white light… When sunlight shines through raindrops, …its speed changes – the light slows down. This causes the light to be refracted. Different colours are refracted at different angles, …so the light is dispersed. We see the dispersed colours as a rainbow.

Final challenge!