Chapter 6 Light Flashcards
What is an incident ray?
The light ray entering a mirror or translucent object.
What is a reflected ray?
The light ray leaving the reflective object.
Where do you see an object laying at the floor of a swimming pool? Why?
Above the original object / it will appear to be floating above the floor of the pool. Because light refracts when it moves from air into water.
What is the angle of incidence and how do you measure it?
The angle of incidence is the angle from where the incident ray hits the mirror; measured from the normal.
What is the relationship between the angle of incidence and the angle of reflection?
The angle of incidence is always equal to the angle of reflection (Law of Reflection)
What is refraction?
The change in direction of light on passing from one medium to another because of a change in speed.
How fast does light travel in air?
300 000km/s
What happens to the speed of light when it passes from air into water or glass?
The light travels more slowly in water or glass.
Name the different colours of a spectrum in order.
Red, orange, yellow, green, blue, indigo, violet
Which direction does a light ray bend when it moves from glass to air?
Away from the normal.
What is the name for the splitting of white light into different colours and what can be used to see this phenomenon?
Dispersion. This can be seen by passing light through a triangular prism.
What is the range of light’s colors called?
The spectrum
Which color of light refracts the least when traveling through a prism? Which refracts the most?
Least - Red
Most - Violet
What colour is produced when red, green and blue light are added together?
White
What colour is produced when red and green light are added together?
Yellow
What happens when you shine white light on a green filter followed by a blue filter?
Only green light passes through the green filter and the other colours are absorbed. The green light is then absorbed by the blue filter, so no light will emerge.
A blue ball appears black. What two colours of light could each be shining on the ball?
Any colour except blue and white
List the 3 primary colours of light
Red, blue, green
Why does a red cube appear black in blue light?
There is no red light for it to reflect, and the blue light is absorbed.
What colour does a white ball appear in green light? Why?
Green, because green light will be reflected on the white surface.
