Phy Flashcards
Light source
An object that produces light they are sometimes hot
Non-luminous
Describes an object that is not a source of light and to see it it has to be reflected onto
How does light travel?
It travels in straight lines and this can be shown on diagrams
Luminous
Describes an object that is a source of light
How do shadows form?
It is formed when an opaque object blocks a light source so it gets less light on that area because light cant bend in one medium
How does the angle of the light source affect the shadow length?
The closer the object is to the light source the bigger the shadow will be and the lower the angle the longer the shadow will be
Reflection
When light bounces off an opaque surface
Transmission
When the object transmits light
Opaque
A material that doesn’t transmit light
Transparent
Describes a material that all light can pass through
Translucent
Allows some light to pass though
What is the law of reflection?
The angle of incidence = the angle of reflection
Why do rays of light bounce off a mirror without being scattered?
Because it has a smooth surface
Where is the normal line?
90 degrees from the mirror
What is the incident ray?
The ray that hits the mirror
What is the reflected ray?
The ray that gets reflected from the mirror
What is the angle of incidence?
The angle between the normal line and the incident ray
What is the angle of reflection?
The angle between the normal line and the reflected ray
Refraction
The change of direction of a light ray when it enters or leaves a transparent material
When we go from air to liquid, what happens?
The light ray slows down and bends toward the normal
When we go from air to solid, what happens?
The light ray slows down and bends toward the normal
When we go from solid to air, what happens?
The light ray speeds up and bends away the normal
When we go from solid to liquid, what happens?
The light ray speeds up and bends away the normal
When we go from liquid to air, what happens?
The light ray speeds up and bends away the normal
When we go from liquid to solid, what happens?
The light ray slows down and bends toward the normal
How does a rainbow form in a rain drop?
First, when it enters the rain drop, it refracts and disperses. Then it reflects and it refracts on its way out because of the different mediums
What are the colors of the spectrum?
Red, orange, yellow, green, blue, indigo, violet
Dispersion
The splitting of white light into separate colours
What color refracts the most?
Purple
