Unit 1 - Physics Flashcards
What are the types of sources of light emissions?
Incandescent, Fluorescent, Chemiluminescent, Bioluminescence, Triboluminescence, Nuclear Fission, Nuclear Fusion (Sun), The Moon, Mirrors & Phosphorescence.
What is Incandescent?
(Luminous) The electrical energy from the socket passes through the filament. The atoms in the filament absorb the electrical energy and converts it into radiant energy which is released as light.
What is Fluorescent?
(Luminous) The electrical energy from the socket passes through the fluorine gas. The atoms of the fluorine gas absorb the electrical energy which is released as light.
What is Chemiluminescent?
(Luminous) Bending a glow stick allows the glass vial inside the plastic tube to break. Mixing the chemicals in the vial with the chemical in the tube. The chemical energy that the molecules have before the reaction is converted into light.
What is Biolumniescence?
(Luminous) When chemiluminescence occurs between two chemicals that are created by a living organism.
What is Triboluminescence?
(Luminous) Light is generated through the breaking of chemical bonds in a material when it is pulled apart, ripped, scratched, crushed or rub. When the crystal structure is broken in a solid the chemical energy is converted into light and is released.
What is Nuclear Fission?
(Luminous) An unstable nucleus, such as uranium breaks apart and it releases energy.
What is Nuclear Fusion?
(Luminous) Hydrogen atoms fuse together to make helium, The nuclear energy stored in the hydrogen atoms is released as light.
What is Phosphorescence?
(Non-Luminous) Light from a luminous source is absorbed by phosphor atoms in the glow in the dark material and light energy is converted into chemical energy.
What is the Electromagnetic Spectrum?
- Radio - used to broadcast radio and live tv.
- Microwaves - used in cooking, radar, telephone and other signals.
- Infrared - transmits heat from the sun, fires, radiators.
- Visible Light - makes things visible to the eye.
- Ultraviolet - absorbed by the skin, used in fluorescent tubes.
- X-rays - used to view the inside of bodies and objects.
- Gamma Rays - used in medicine to kill cancer cells.
What is the Law of Refraction?
It states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of refraction.
What does MALT stand for?
M - Magnification - smaller/larger/the same
A - Attitude - upright/inverted
L - Location - closer/further/the same
T - Type - virtual/real
What is the Thin Lens Equation?
1/f = 1/do + 1/di
used to calculate the focal length, distance of the object, or distance of the image
What is GRASP?
G (given) R (required) A (analysis) S (solve) P (paraphrase)
How do you calculate the Index of Refraction (using diagrams)?
- n = c/v
(or v = c/n) - n = r.d/a.d
(r.d = n/a.d)
How do you calculate the Index of Refraction (using 2 different mediums)?
Snell’s Law:
n1sinθ1/sinθ2 - n2θ2/sinθ2
What is Partial Refraction?
When light hits the surface of a mirror, 90% of the light reflects at the air/glass surface, but 10 % of the light enters the glass and refracts.
What is Partial Reflection?
90% of the light refracts at the boundary, but 10% of the light reflects from the surface.
What is Total Internal Reflection?
As light travels from a more optically dense medium into a less dense medium, the incident angle reaches its critical angle. When the incident angle is larger than the critical angle, it refracts at an angle greater than 90 degrees (TIR).This causes the light to remain in the dense medium and it appears to reflect off the boundary.
How does Laser Surgery work?
- Using a laser to remove tiny pieces of the cornea, therefor reshaping it.
- By reshaping, this allows the cornea to bend the light so it is in focus when it hits the retina.
- It helps to correct vision problems caused by refractive errors.
How do Inferior Mirages work?
Cold air is denser than warm air and has a greater index of refraction. As light passes from colder air across a sharp boundary to significantly warmer air, the light rays bend up in a concave upward direction. This results in the inferior image of the sky appears to be on the ground.
How do Superior Mirages work?
When the air below the line of sight is colder than that above. Since the light rays are bent down, the image appears above the true object.
How do 2-way mirrors work?
They work because most of the light is reflected and a small amount enters the darkened room behind. The light refracts as it enters & leaves the glass.
How do Fiver Optic tubes work?
Light rays undergo total internal reflection, “bouncing” from side to side down the tube.
