Physics 1 Flashcards
What are objects called when they don’t produce their own light? How do we see them?
Non luminous they reflect light
What is light?
A form of radiant energy
What part of light do our eyes react to?
Visible light
What is the electro magnetic spectrum?
High to low Gamma radiation X-rays Ultra violet Visible Infra red Microwave Radio
What is the colour spectrum?
Violet Indigo Blue Green Yellow Orange Red
How fast does light travel?
300,000 km/per second
How does light travel? What is it called?
In straight lines. It never bends. It’s called the rectilinear propagation of light
Remember that light doesn’t need a medium to travel though
It can travel through space (vacuum)
What are the three things light can do?
Be absorbed reflected and transmitted
Something that produces its own light
Luminous
Sun
The production of light due to high temperature
Example
Incandescence
Light bulb
The process of producing light by passing an electric current through a gas
Ex
Lightning
Production of light by the absorption of ultra violet light resulting in the emission of visible light over an extended period of time
Ex
Phosphorescence
Glow in the dark toys
The immediate emission of visible light as a result of the absorption of ultra violet light
Ex
Detergent
Fluorescence
The direct production of light as the result of a chemical reaction with little or no heat produced
Chemiluminescence
Glow stick
The production of light in living organisms as the result of a chemical reaction with little or no heat produced
Bioluminescence
Glow worms
The production of light from friction as a result of scratching, crushing, or rubbing certain crystals.
Triboluminescence
Rubbing Quartz crystals together
Light produced as a result of an electric current flowing in semiconductors
Light emitting diode
Christmas lights
Transparent
Example
All or most of the light is transmitted
Window glass
Translucent
Example
Only some light is transmitted while the rest is absorbed or reflected
Wax paper
Opaque
Example
No light is transmitted
Brick wall
What are the two laws of reflection?
- The angle of incidence always equals the angle of reflection
- The incident Ray, the normal , and the reflected Ray all lie on the same plane.
What are the characteristics of images?
S size (height) A attitude (upright or inverted) L location: distance form mirror to image T type (real or virtual)
