Characteristics of Light
What is the speed of light?
3.0 x 108 m/s
What is the angle of incidence vs angle of reflection?
Incidence - the angle of the light ray that is headed toward the mirror that will soon reflect
Reflection - the angle at which the light ray reflects; is equal to the angle of incidence
What causes the speed of light to vary?
The medium it's travelling through
Where are rods and cones located?
Retina
Which is the most efficient lightbulb?
LED
List 3 uses for UV lights.
tanning, production of vitamin D, kills bacteria in food and water, "black" light, UV lasers, astronomy
If an object is placed at C, where would the image be and what would be it's characteristics?
Located at C
- same size, inverted, real
What is the formula to calculate the index of refraction and what does each value mean?
n = IoR
c= speed of light (vacuum)
v = speed of light (in medium)
What is the purpose of rods and cones?
To send messages to the brain through the optic nerve
Which direction do light rays from an incandescent lightbulb go?
In all different directions
What is the energy relative to shorter wavelengths?
Shorter wavelengths = higher energy
What is the difference between a real image and a virtual image in a mirror?
Virtual - it appears as though light is coming from the image, however the light source is coming from the object
When an object looks like it's more shallow in the water than it really is, what is that phenomenon called?
Apparent depth
What is the thin lens equation?
1/do + 1/di = 1/f
When organisms glow.. what is this called, and provide 2 examples of organisms that glow.
Bioluminescence
- bacteria, algea, fungi, marine invertebrates, fish, glow worms, fireflies
When light hits an object, it can be...?
Reflected, absorbed, or transmitted
What happens to the light rays in a convex mirror?
They always diverge
When drawing a converging lens diagram, where do we put F ' ?
On the same side as the object
Toy height = 8.4cm infront of a converging lens, an inverted, real image of 23 cm is noticed on the other side of the lens. What is the magnification?
-2.7
- negative because it's an inverted image
What does LED stand for?
Light-Emitting Diode
What is the SALT of an object in a plane mirror?
- same size
- backwards/reversed
- behind the mirror
- virtual
Find the image in the picture drawn on the board.
Before F
In a DIVERGING lens, if an object is placed beyond F, where will the image be located and what will it's characteristics be?
It will be located in front of F; upright, smaller, virtual
When is the focal length of an image positive vs negative?
Positive - converging lens
Negative - diverging lens
Recall the video of crushing lightsavers, what was the light production called?
Triboluminescence