Waves, Light, and Colour Flashcards
What is the crest of a wave?
The farthest point above the resting position
What is the trough of a wave?
The farthest point below the resting position
What is wavelength?
The distance between two adjacent crests or two adjacent troughs
What is amplitude?
The maximum distance above or below the resting position
What is frequency?
The number of cycles of a vibration in a period of time
What is hertz?
The unit of measurement to indicate the frequency of a wave
What are the 7 colours of the visible spectrum?
Red, orange, yellow, green, blue, indigo, violet
Which colour would have the lowest frequency?
Red
Which colour would have the highest frequency?
Violet
White light is a mixture of what?
All the colours of the rainbow
When white light goes into a prism, what happens?
It breaks up into all of the colours of the rainbow, called the full spectrum
When pure colours pass through a prism, what happens?
They can’t be broken up anymore
Why are fruits and vegetables particular colours?
Because they reflect the one colour you see and absorb all the rest of the colours
We don’t see things, we see what?
Light bouncing off of things
When light is absorbed, what is it changed to?
Heat
Particles in paint that absorb some colours and reflect others are called what?
Pigment
Mixing all colours of light gives what?
White light
Mixing all colours of paint results in what colour?
Brown
When objects absorb all or most of the colours of light that hit them, they appear what?
Black
Light is produced by neon tubes by what?
High voltage electricity to excite neon gas so that light is emitted
What colour objects reflect all colours of light?
White
What is the colour of an object?
The colour of light it reflects
Black absorbs what from the sun?
Heat, and it reflects very little
White reflects most of the what from the sun?
Heat, and it absorbs very little
Why is the sky blue?
Because air molecules in the sky scatter light, and they scatter blue light more than other colours
When black objects absorb light, what happens?
They got warm/hot
What is the dark part of a shadow called?
The umbra
What is the lighter part of a shadow called?
The penumbra
