Unit 3

Question 1

*Define Light

Answer 1

Light is a form of energy that you can see

Question 2

Define Radiate

Answer 2

Spreads out

Question 3

Define Radiation

Answer 3

The transfer of radiant energy (light) that does not require matter (travels in waves)

Question 4

Define Radiant Energy

Answer 4

Energy such as light that travels in waves

Question 5

Define Luminous

Answer 5

Objects that emit light

Question 6

Define Non-Luminous

Answer 6

Objects that do not emit light

Question 7

*How do incandescent sources produce light?

Answer 7

Objects are heated to such high temperatures that they emit light

Question 8

What is the energy pathway of incandescent sources?

Answer 8

Electrical Energy -> Thermal Energy -> Visible Light

Question 9

How do florescent sources produce light?

Answer 9

Objects that absorb high energy UV light to glow and emit visible light

Question 10

What is the energy pathway of florescent sources?

Answer 10

Electrical Energy -> Energy absorbed by Hg -> UV light energy -> Energy absorbed by phosphor coating -> Visible Light

Question 11

How do phosphorescent sources produce light?

Answer 11

An object that absorbs, stores, ad emits light energy.

Question 12

What is the energy pathway of phosphorescent sources?

Answer 12

Electrical Energy -> Absorbed and Stored -> Visible Light

Question 13

How do Chemiluminescent sources produce light?

Answer 13

An object that emits light from a chemical reaction

Question 14

What is the energy pathway of chemiluminescent sources?

Answer 14

Chemical Energy -> Visible Light

Question 15

*How do Bioluminescent sources produce light?

Answer 15

A living organism that emits light

Question 16

*What is the energy pathway of bioluminescent sources?

Answer 16

Living Organism -> Visible Light

Question 17

How do you determine the cost of energy?

Answer 17

1. Convert W to KW (divide by 1000)
2. Calculate KW hours by multiplying KW x hours
3. Calculate cost by multiply KW h x cost in cents
   =___cents/KW h

Question 18

What are the observations the ray model of light is based on?

Answer 18

• explains shadows

- light rays travel in straight lines from its source

Question 19

Define Ray

Answer 19

A straight line that represents the path of a beam of light

Question 20

What is included in a ray diagram?

Answer 20

incident ray, reflected ray, normal, reflecting surface, angle of incident, angle of reflection

Question 21

*What happens when light hits transparent material?

Answer 21

All light goes through

Question 22

*What happens when light hits translucent material?

Answer 22

Some light goes through and some light bounces off

Question 23

*What happens when light hits opaque materials?

Answer 23

Light bounce off

Question 24

*Define Reflection

Answer 24

Light strikes a surface then bounce off it

Question 25

Define Incident Ray

Answer 25

A ray of light from a light source that reflects off a surface

Question 26

Define Reflected Ray

Answer 26

A ray of light that bounce off a surface

Question 27

Define Normal

Answer 27

The line that is 90 degrees the reflecting surface

Question 28

Define Angle of Incidence

Answer 28

The angle between the Normal and the incident ray

Question 29

Define Angle of Reflection

Answer 29

The angle between the normal and the reflected ray

Question 30

*Define Plane Mirror

Answer 30

A mirror with a flat surface

Question 31

*Define the Law of reflection (2 point)

Answer 31

1. Angle i = Angle r | 2. i, normal, and r are all in the same plane

Question 32

**Label a diagram of a reflecting surface

Answer 32

____

Question 33

*Define Refraction

Answer 33

The bending of light as it moves through different mediums of different densities

Question 34

Define Angle of Refraction

Answer 34

The new direction of light; angle between the normal line and refracted ray

Question 35

*Define Absorbtion

Answer 35

occurs mostly on rough, dark, opaque surfaces

Question 36

Define Reflection

Answer 36

Light bounce off a surface; occurs when light hits a shiny, smooth surface

Question 37

Define Refraction

Answer 37

Travels through a surface in a different direction; occurs when light hits a different, transparent medium

Question 38

*Define Mirage

Answer 38

Occurs when light refracts through different densities of air

Question 39

*What does a concave lens do to light

Answer 39

Diverges light

Question 40

*What does a convex lens do to light

Answer 40

Converges light to a focal point

Question 41

*What does a convex lens with a smaller curve do to light

Answer 41

Focal point forms closer to lens

Question 42

*What does a convex lens with a larger curve do to light

Answer 42

Focal point forms farther away from lens