Light Booklet Flashcards
What is the word that means light travels in straight lines
Rectilinear propogation
What are the 3 rules for drawing ray diagrams
- Light rays are always drawn in straight lines with a sharp pencil and a ruler
- They always have one arrow per straight line to show the direction it is travelling in
- The light ray always travels away from the light source
What is the darkest point of a shadow called
The umbra
Large sources of light often have a blurred edge called a
Penumbra
White light is made up of…
Red, orange, yellow, green, blue, purple
What does rectilinear propagation mean
Light always travels in straight lines
How does light travel
In straight lines
How do we see colour
As the lines gut is reflected into our eyes and all the colours but one is absorbed the one left reflects into our eyes
What is the order of the colour spectrum
Red yellow green blue indigo violet
What is a solar eclipse
When the moon goes in front of the sun
What is a lunar eclipse
When the earth goes in front of the moon
What is the blurred part of the shadow called
Penumbra
What is the sharp area of the shadow called
Umbra
When are shadows atbthere shortest
Midday
When are shadows at there longest
Evening or morning
What happens when you shine a light into a prism
The light refracts and disperses spliiting up white light
What is refraction
When light speeds up or slows down and changed direction
Do shadows get longer or shorter when the light source gets closer
Longer
What is a laser
A concentrated powerful beam of light
True or False:The angle of incidence is equal to the angle of reflection
True
Name an experiment that we did to prove that light travels in straight lines
Pinhole
Explain how the pinhole experiment works
You get three pieces of cardboard and making sure that they are all in line shine a light through.Put your hand behind the last piece of cardboard and if you see a light on your hand it worked.
What does the experiment prove
If light didn’t travel in straight lines it could not have got through the holes
