Physics-Unit 7-Lessons 7, 8 and 9 Dispersion, Colour and Looking at coloured objects
1) state the number of times that light is refracted when it passes through prism 2) State the colours of the spectrum from the colour that is refracted most to the colour that is refracted least
1) 7 times 2) violet, Indigo, blue, green, yellow, orange then red
A football team wears a yellow shirt and white shorts, Tell what the kit look like in: 1) red light 2) green light 3) blue light
1) red shorts and red shirt 2) green shorts and green shirt 3) blue shorts and black shirt
Who made the first colour film ?
Ardeshir Irani who was Hindi
who demonstarted that the sunlight is split into colours?
Isaac Newton
who discovered how the rainbow is formed?
an iranian scientist Al-Farisi
Paint vs Light
an object looks white because all colours or nearly all colours reflect white. an object looks black because none or almost none of the colours are reflected
why do we call red, green and blue the primary colours?
because if you mix any 2 colours you will never get the primary colours
You are looking at yellow flower growing outside in the sunshine. Explain why it looks yellow
because yellow will absorb all the colours of light except the colour that it appears to be which is yellow
How do colour filters work?
by absorbing some colour and transmitting other colours
How did Isaac Newton show how to recombine the spectrum colours back into white colour?
by using 2 prisms.
what can you use to make different light colours?
colour filters are used to produce different colours from white light
What is a spectrum?
coloured band produced when a beam of light passes through a prism
if you mix blue and green what do you get?
cyan
How is a spectrum formed?
is formed when different coloured are refracted by different amounts
How is a rainbow formed?
it is formed when raindrops split sunlight into colours
which colour does the filter let if you shine white light through a red filter?
it will only let red light through. It means red light is transmitted and the rest of the colours are absorbed
if you mix red and blue what do you get?
magenta
The secondary colours of light are
magenta, cyan, yellow
what do you get if you mix any of the 2 primary colours?
one of the secondary colour
which colour refracts the least and why?
red because it slows down the least
The primary colours of light are
red, green, blue
what are the colours of spectrum?
red, orange, yellow, green, blue, indigo, violet
what do you get if you mix all the colours of paint?
the paint looks black
which colours do filters absorb?
they absorb all colours except the ones they transmit
which colour refracts the most and why?
violet because it slows down the most
dispersion of colors
when the prism splits white colour into the colours of spectrum is called dispersion
when do you see a rainbow?
when you are facing falling rain and the sun behind you. raindrops behave like small prisms and the sunlight is refracted, reflected and dispersed so that you see a spectrum
What do you get if you mix all 3 primary colours?
white colour
if you mix red and green what do you get?
yellow
Explain how you can have refraction without dispersion, but dispersion without refraction
you can't have dispersion without refraction because refraction which the speed of light has can be refracted with different amounts in order to get the dispersion of colours. You can have refraction without dispersion because you can have refraction of one colour.
what do you get if you mix all the colours of light?
you get white light