Unit C: Section 1.0 & 2.0 Flashcards Preview

Grade 8: Science > Unit C: Section 1.0 & 2.0 > Flashcards

Flashcards in Unit C: Section 1.0 & 2.0 Deck (41):
1

What was the problem with Pythagoras' theory about light?

We would be able to see in the dark

2

What did Euclid discover?

When you shine a beam of light on a flat mirror the angle between the incoming beam and the mirror is equal to the angle of the reflected beam

3

What did Al-Haytham discover about light?

He said that light bounces off objects and then into the eye

4

What is white light made of?

Newton discovered that by shining light through a prism it is a combination of different colors

5

What are the properties of light?

Light travels in straight lines
Light can be reflected
Light can bend
Light is a form of energy

6

What did Ptolemy discover?

He discovered how light bends when it goes from air to glass

7

What is the formula for the speed of light?

Speed=distance (km)
-------------
time (sec)

8

What is an optical device?

Any technology that uses light

9

Who discovered microscopes?

Hans and Zacharias

10

How do microscopes work?

Light is reflected from a mirror and goes through the specimen and then to the objective and then eye piece

11

Who discovered telescopes?

Galileo

12

What are the two types of telescopes?

Reflecting and refracting

13

Describe refracting telescopes

Refracting telescopes have 2 lenses one on each end of a long tube, the larger lens gathers light and focuses the light to the eyepiece

14

Describe a reflecting telescope

It uses a large circular mirror that curves inward to gather light. Another mirror that directs it to a an eyepiece

15

How do binoculars work?

It has an objective lens and to reflective prisms that direct light to the eye

16

What did Pythagoras believe about light?

He thought light consisted of beams that came from ones eyes

17

What is a ray diagram?

Ray digraph show how light travels

18

What does transparent mean?

You can see through it clearly and it has little or no reflection

19

What does translucent mean?

It allows some light to pass through

20

What does opaque mean?

Does not allow light to pass through

21

What does non-luminous mean?

They do not produce light

22

What does luminous light mean?

It produces light

23

What is regular reflection?

It is when light hits a smooth surface and reflects in all the same direction

24

What is diffuse reflection?

When light hits a rough surface and reflects in all different angles

25

What makes a good reflector?

A material that is shiny and smooth

26

What is the incident Ray?

The incoming light

27

What is the reflecting Ray?

The beam that bounces off a surface

28

What is a plane mirror?

A flat mirror

29

What is a normal?

An imaginary line perpendicular to a Duracell

30

What is the law of reflection?

The angle of reflection is equal to the angle of incidence

31

What is a concave mirror?

It has a surface that curves inward

32

What is a focal point?

When all the Rays intersect

33

What does a concave mirror do to images?

If the image is between the focal point and the mirror than it is upright

34

What is a convex mirror?

A mirror with a surface curved outwards

35

What does a concave mirror do to light rays?

It spreads out light

36

What is refraction?

The bending of light as it moved from one medium to another

37

Why does light refract?

When it goes from one density to the other it slows down

38

What is a lens?

If is a piece of curved glass or other transparent material

39

What happens when light passes through a concave lens?

The Rays spread out or diverge

40

What happens when light goes through a convex lens?

They focus into a focal point

41

What is a real image?

Light can be projected, but they are upside down