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)
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1
Q

What was the problem with Pythagoras’ theory about light?

A

We would be able to see in the dark

2
Q

What did Euclid discover?

A

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
Q

What did Al-Haytham discover about light?

A

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

4
Q

What is white light made of?

A

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

5
Q

What are the properties of light?

A

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

6
Q

What did Ptolemy discover?

A

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

7
Q

What is the formula for the speed of light?

A

Speed=distance (km)
————-
time (sec)

8
Q

What is an optical device?

A

Any technology that uses light

9
Q

Who discovered microscopes?

A

Hans and Zacharias

10
Q

How do microscopes work?

A

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

11
Q

Who discovered telescopes?

A

Galileo

12
Q

What are the two types of telescopes?

A

Reflecting and refracting

13
Q

Describe refracting telescopes

A

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
Q

Describe a reflecting telescope

A

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

15
Q

How do binoculars work?

A

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

16
Q

What did Pythagoras believe about light?

A

He thought light consisted of beams that came from ones eyes

17
Q

What is a ray diagram?

A

Ray digraph show how light travels

18
Q

What does transparent mean?

A

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

19
Q

What does translucent mean?

A

It allows some light to pass through

20
Q

What does opaque mean?

A

Does not allow light to pass through

21
Q

What does non-luminous mean?

A

They do not produce light

22
Q

What does luminous light mean?

A

It produces light

23
Q

What is regular reflection?

A

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

24
Q

What is diffuse reflection?

A

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

25
Q

What makes a good reflector?

A

A material that is shiny and smooth

26
Q

What is the incident Ray?

A

The incoming light

27
Q

What is the reflecting Ray?

A

The beam that bounces off a surface

28
Q

What is a plane mirror?

A

A flat mirror

29
Q

What is a normal?

A

An imaginary line perpendicular to a Duracell

30
Q

What is the law of reflection?

A

The angle of reflection is equal to the angle of incidence

31
Q

What is a concave mirror?

A

It has a surface that curves inward

32
Q

What is a focal point?

A

When all the Rays intersect

33
Q

What does a concave mirror do to images?

A

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

34
Q

What is a convex mirror?

A

A mirror with a surface curved outwards

35
Q

What does a concave mirror do to light rays?

A

It spreads out light

36
Q

What is refraction?

A

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

37
Q

Why does light refract?

A

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

38
Q

What is a lens?

A

If is a piece of curved glass or other transparent material

39
Q

What happens when light passes through a concave lens?

A

The Rays spread out or diverge

40
Q

What happens when light goes through a convex lens?

A

They focus into a focal point

41
Q

What is a real image?

A

Light can be projected, but they are upside down