Chapter 4 | How Light Works Flashcards
Light is?
An electromagnetic wave that is visible to the human eye.
No medium needed.
How does light travel?
Light rays travel in straight lines.
When light waves strike an object what 3 things can happen?
-Reflection The light rays bounce off/reflect off the object -Refraction The light rays travel through the object -Absorption
What is reflection?
It is the rebounding of light when it passes through one medium and rebounds on a different medium and returns through the same medium that it started. Example: Open window (air) -> Table (solid) -> Eye (air)
What is the law of (specular) reflection?
The angle of reflection is equal to the angle of incidence.
What are the names of rays in a reflection?
1. Incident Ray Ray that hits the object. 2. Reflected Ray Rebounds. 3. Normal Line Perpendicular to object. 4. Angle of Incidence Angle formed by incident ray and normal line. 5. Angle of Reflection Angle formed by reflection + normal line.
What is the object/thing called when light rays reflect off of it?
It’s the Plane Mirror.
What are the two (2) types of reflections?
1. Diffuse Reflection The rays hit a rough surface, going in all directions. Example: ground, paper 2. Specular Reflection -Rays hit a smooth surface -Lines of reflection are parallel Example: mirror, still lake
Specular Reflections are on?
Plane Mirrors
The Image in a mirror appears…
Behind mirror/same distance
An Image in a mirror is?
- The same size
- Virtual
- Horizontally inverted (left & right switched)
How do we use Plane Mirrors?
-Rear View Mirrors
-Dentist Mirrors
-Telescope/Periscopes
By using these types of Mirrors, we increase our field of vision and change the trajectory of the rays.
Refraction is?
It’s when the Light Rays deviate as it passes through one medium then another.
