Unit 1 - Physics

Question 1

What are the types of sources of light emissions?

Answer 1

Incandescent, Fluorescent, Chemiluminescent, Bioluminescence, Triboluminescence, Nuclear Fission, Nuclear Fusion (Sun), The Moon, Mirrors & Phosphorescence.

Question 2

What is Incandescent?

Answer 2

(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.

Question 3

What is Fluorescent?

Answer 3

(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.

Question 4

What is Chemiluminescent?

Answer 4

(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.

Question 5

What is Biolumniescence?

Answer 5

(Luminous) When chemiluminescence occurs between two chemicals that are created by a living organism.

Question 6

What is Triboluminescence?

Answer 6

(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.

Question 7

What is Nuclear Fission?

Answer 7

(Luminous) An unstable nucleus, such as uranium breaks apart and it releases energy.

Question 8

What is Nuclear Fusion?

Answer 8

(Luminous) Hydrogen atoms fuse together to make helium, The nuclear energy stored in the hydrogen atoms is released as light.

Question 9

What is Phosphorescence?

Answer 9

(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.

Question 10

What is the Electromagnetic Spectrum?

Answer 10

1. Radio - used to broadcast radio and live tv.
2. Microwaves - used in cooking, radar, telephone and other signals.
3. Infrared - transmits heat from the sun, fires, radiators.
4. Visible Light - makes things visible to the eye.
5. Ultraviolet - absorbed by the skin, used in fluorescent tubes.
6. X-rays - used to view the inside of bodies and objects.
7. Gamma Rays - used in medicine to kill cancer cells.

Question 11

What is the Law of Refraction?

Answer 11

It states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of refraction.

Question 12

What does MALT stand for?

Answer 12

M - Magnification - smaller/larger/the same
A - Attitude - upright/inverted
L - Location - closer/further/the same
T - Type - virtual/real

Question 13

What is the Thin Lens Equation?

Answer 13

1/f = 1/do + 1/di

used to calculate the focal length, distance of the object, or distance of the image

Question 14

What is GRASP?

Answer 14

G (given)
R (required)
A (analysis)
S (solve)
P (paraphrase)

Question 15

How do you calculate the Index of Refraction (using diagrams)?

Answer 15

1. n = c/v
   (or v = c/n)
2. n = r.d/a.d
   (r.d = n/a.d)

Question 16

How do you calculate the Index of Refraction (using 2 different mediums)?

Answer 16

Snell’s Law:

n1sinθ1/sinθ2 - n2θ2/sinθ2

Question 17

What is Partial Refraction?

Answer 17

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.

Question 18

What is Partial Reflection?

Answer 18

90% of the light refracts at the boundary, but 10% of the light reflects from the surface.

Question 19

What is Total Internal Reflection?

Answer 19

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.

Question 20

How does Laser Surgery work?

Answer 20

• 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.

Question 21

How do Inferior Mirages work?

Answer 21

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.

Question 22

How do Superior Mirages work?

Answer 22

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.

Question 23

How do 2-way mirrors work?

Answer 23

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.

Question 24

How do Fiver Optic tubes work?

Answer 24

Light rays undergo total internal reflection, “bouncing” from side to side down the tube.