Science Flashcards
(179 cards)
1
Q
What is a regular reflection?
A
Reflection of light from a smooth, shiny surface
2
Q
Reflection of light from a smooth shiny surface is called…
A
A regular reflection
3
Q
What is a diffuse reflection?
A
Reflection of light from a rough surface
4
Q
Reflection of light from a rough surface is called…
A
A diffuse reflection
5
Q
What is scattering?
A
Scattering occurs when light waves travelling in one direction are made to travel in many directions. The dust particles scatter the light waves in a sunbeam,
6
Q
When is the image virtual in a concave mirror?
A
It’s virtual when the object is in between the focal point and the mirror.
7
Q
When is the image real in a concave mirror?
A
It’s real when the object is beyond the focal point.
8
Q
What is a real image?
A
A real image is one that forms where rays converge.
9
Q
What is a concave mirror?
A
A mirror that curves inward is called a concave mirror.
10
Q
A mirror that curves inward is called…
A
A concave mirror
11
Q
What is the focal point in a mirror?
A
The point where light rays parallel to the optical axis converge after being reflected by a concave mirror is the focal point.
12
Q
What is the focal length in a mirror?
A
The distance along the optical axis from the mirror to the focal point is the focal length.
13
Q
The lesser curve of a mirror, the ……
A
longer its focal length
14
Q
What determines the type of image formed in a concave mirror?
A
The position of an object compared to the focal point determines the type of image formed by a concave mirror.
15
Q
What is a convex mirror?
A
A mirror that curves outward, like the back of a spoon, is called a convex mirror.
16
Q
What happens to light rays after they strike a surface of a convex mirror?
A
They diverge, or spread apart.
17
Q
When rays parallel to the optical axis strike a concave mirror, the reflected rays…
A
converge, or come together.
18
Q
What is a virtual image?
A
It’s an image that forms from light rays that diverge, or change direction
19
Q
What is the normal?
A
An imaginary line that is perpenduclar to a reflecting surface.
20
Q
What is the incident ray?
A
The light ray moving towards the surface.
21
Q
An imaginary line perpendicular to a reflecting surface is called…
A
the normal
22
Q
The light ray moving towards the surface is called…
A
The incident ray
23
Q
When is the angle of incidence formed?
A
When an incident ray meets the normal
24
Q
When is the angle of reflection formed?
A
The angle formed between the reflected ray and the normal. It is equal to the angle of incidence, but on the opposite side of the normal.
25
What is the law of reflection?
When a wave is reflected from a surface, the angle of reflection is equal to the angle of incidence.
26
What is reflection?
the bouncing of a wave off a surface
27
What is the image orientation of a plane mirror?
upright
28
What is the image size of a plane mirror?
same size as the object
29
What is the image type of a plane mirror?
always virtual
30
What are examples of a plane mirror?
bathroom mirror, dressing mirror
31
What is the image orientation of a concave mirror?
Upright when the object is in between the mirror and the focal point, Inverted when the object is beyond the focal point.
32
What is the image size of a concave mirror?
Lagrer if its closer to the mirror, Smaller if its farther from the mirror
33
What is the image type of a concave mirror?
virtual if the object is between the focal point and the mirror, real if the object is beyond the focal point.
34
What are examples of a concave mirror?
satellite dish, flashlight , telescope
35
What is the image orientation of a convex mirror?
upright
36
What is the image size of a convex mirror?
smaller than the object, or reduced
37
What is the image type of a convex mirror?
always vitual
38
What are examples of a convex mirror?
back of a spoon, store security mirror
39
What are rays?
Lines of light that are represented in a model as straight arrows.
40
Lines of light that are represented in a model as straight arrows are called...
rays
41
The light ray moving away from a surface is called....
the reflected ray
42
A line perpendicular to the center of the mirror is called...
the optical axis
43
What image is formed in a concave mirror if the object is at the focal point?
No image is formed
44
Why can you see your reflection in smooth, shiny surfaces but not in a piece of paper or a painted wall?
The law of reflection applies whether the surface is smooth or rough. On smooth surfaces, reflected rays stay organized, so you see clear images. On rough surfaces, rays scatter in different directions, so no clear image forms
45
When light strikes an uneven surface, the angle of reflection (.......) to the angle of incidence at each point, however(......)
equal, rays reflect in different directions.
46
Why do dust particles reflect light waves in many different directions?
because they have different shapes and sizes.
47
The angle of incidence is the angle between the incident ray and the...
normal
48
The light rays moving towards the surface is called...
incident rays
49
Virtual images are always (............) on the (........) side of the mirror
right side up, opposite
50
A real image is the image formed when rays .......
converge
51
The reflected rays in (.......) reflection are parallel
regular
52
What is refraction?
The change in direction of a wave as it changes speed while moving from one medium to another is called refraction.
53
The change in direction of a wave as it changes speed while moving from one medium to another is called...
refraction
54
A medium that has a high index of refraction is sometimes called...
slow
55
A medium that has a relatively low index of refraction, such as air, is called...
fast
56
If the index of refraction is the same...
the light will not refract
57
The angle that light refracts is dependent on...
the difference between the indices of refraction of the two objects.
58
A light ray refracts (......) the normal when it moves into a slower medium and strikes the boundary at an angle.
towards
59
A light ray refracts (......) the normal when it moves into a faster medium and strikes the boundary at an angle.
away from
60
What is a lens?
A lens is a transparent object with at least one curved side that causes light to change direction.
61
Light (......) as it passes through a lens
refracts
62
The greater the curve of a lens...
the more the light refracts.
63
What does the direction of refraction depend on?
It depends on whether the lens is curved outward or inward
64
What is a convex lens?
A lens that is thicker in the middle than at the edges
65
A lens that is thicker in the middle than at the edges is called...
convex lens
66
Light rays that move through a convex lens....
come together, or converge
67
What is a concave lens?
A lens that is thicker at the edges than in the middle
68
A lens that is thicker at the edges than in the middle is called...
concave lens
69
Light rays that move through a concave lens...
spread apart, or diverge
70
A convex lens refracts light....
inward
71
A concave lens refracts light....
outward
72
What is the focal point in a lens?
The point where light rays parallel to the optical axis converge after passing through a lens.
73
What is the focal length in a lens?
The distance along the optical axis between the lens and the focal point.
74
What depends the type of image formed in a convex lens?
The location of the object.
75
concave lens always forms...
virtual, small, and upright image
76
convex lens can form
real or virtual images
77
If an object is more than one focal length from the lens in a convex lens, the image is....
real, inverted and smaller
78
If an object is less than one focal length from the lens in a convex lens, the image is...
virtual, upright and larger
79
What is the image type of a convex lens?
real or virtual depending on the location of the object
80
What is the image size of a convex lens?
bigger or smaller depending on the distance from the lens compared to the focal point
81
What is the image direction of a convex lens?
inverted or upright depending on the distance from the lens compared to the focal point
82
What are examples of a convex lens?
magnifying glass, projector
83
What is the image type of a concave lens?
always virtual
84
What is the image size of a concave lens?
always smaller
85
What is the image direction of a concave lens?
always upright
86
What are the examples of a concave lens?
peephole, glasses for nearsighted people
87
As light moves through a slower medium, the angle of incidence is (.....) than the angle of refraction
greater
88
A light moves through a faster medium, the angle of incidence is (......) than the angle of refraction
less
89
What is rotation?
A spinning motion is called rotation.
90
A spinning motion is called...
rotation
91
Where does Earth rotate?
Earth rotates on an imaginary line through its center.
92
What is rotation axis?
The line on which an object rotates is the rotation axis.
93
Earth rotates on its rotation axis in a...
counter clockwise direction, from west to east
94
How long does one complete rotation of earth take?
24 hours
95
What is an orbit?
The path an object follows as it moves around another object is an orbit.
96
What is revolution?
The motion of one object around another is revolution.
97
How long does it take for earth to make one complete revolution around the sun?
365.24
98
Why does Earth orbit the sun?
Because of gravity. The Sun and Earth pull on each other, and the size of this pull depends on the mass and distance The Sun’s strong pull keeps Earth moving around it in a path called an orbit.
99
Earth's rotation axis is...
tilted
100
The tilt of Earth's rotation axis is always in the (.....) direction by the (......) amount, this means that....
same, same, it means that during half of Earth's orbit, the north end of the rotation axis is tilted toward the sun. During the other half of Earth's orbit, the north end of the rotation is is tilted away from the sun.
101
When is Earth closest to the sun?
January 3rd
102
When is Earth farthest from the sun?
July 4th
103
What would happen if the gravity between Earth and the Sun were to somehow stop? Why?
Earth would fly off into space in a straight line, because the pull of the Sun's gravity keeps Earth revolving around the Sun in a nearly circular orbit.
104
Why does the Sun appear to move from east to west across the sky?
Because Earth rotates from west to east, it makes the Sun appear to move from east to west across the sky — but it's really Earth that’s spinning.
105
Why is it warmer at the equator and colder at the poles?
Earth’s surface is curved, so sunlight hits the equator directly but spreads out more near the poles. This makes the equator warmer and the poles colder because the same sunlight is spread over a larger area at the poles.
106
What causes the seasons to change?
The tilt of Earth;s rotation axis, combined with Earth's motion around the sun.
107
During one half of the Earth's orbit, the north end of the rotation axis is away from the sun, so...
The northern hemisphere receives less solar energy than the southern hemisphere. Temperatures increase in the southern hemisphere, and they decrease in the northern hemisphere. This is when fall and winter occur in the northern hemisphere, and spring and summer occur in the southern hemisphere.
108
During one half of the Earth's orbit, the north end of the rotation axis is toward the sun, so...
The northern hemisphere receives more solar energy than the southern hemisphere. Temperatures increase in the northern hemisphere, and they decrease in the southern hemisphere. This is when spring and summer occur in the northern hemisphere, and spring and summer occur in the southern hemisphere.
109
Days last longer in (.........), and nights last longer in (.......)
the rotation axis that is toward the sun, the rotation axis that is away from the sun
110
What is a solstice?
A day when Earth's rotation axis is the most toward or away from the sun.
111
A day when Earth's rotation axis is the most toward or away from the sun is called...
A solstice
112
What is an equinox?
A day when Earth's rotation axis is leaning along Earth's orbit, neither toward or away from the sun.
113
A day when Earth's rotation axis is leaning along Earth's orbit, neither toward or away from the sun is called...
An equinox
114
March equinox to June solstice
When the north end of the rotation axis gradually points more and more toward the sun, the northern hemisphere gradually receives more solar energy. This is Spring in the northern hemisphere.
115
June solstice to September equinox
The north end of the rotation axis continues to point toward the sun but does so less and less. The northern hemisphere starts to receive less solar energy. This is summer in the northern hemisphere.
116
September equinox to December solstice
The north end of the rotation axis points more and more away from the sun. The northern hemisphere receives less and less solar energy. This is fall in the northern hemisphere.
117
December solstice to March equinox
The north end of the rotation axis continues to point away from the sun but does so less and less. The northern hemisphere starts to receive more solar energy. This is winter in the northern hemisphere.
118
The sun's apparent path through the sky in the northern hemisphere is lowest on (........) and highest on (.........)
December solstice, june solstice
119
When is the December solstice?
December 21 or 22
120
What happens on December solstice?
the north end of earth's rotation axis is away from the sun
days in the northern hemisphere are shortest and nights are longest, winter begins
days in the southern hemisphere are longest and nights are shortest, summer begins
121
When is September equinox?
September 22 or 23
122
What happens on September equinox?
the north end of earth's rotation axis leans along earth's orbit
there are about 12 ours of daylight and 12 hours of darkness everywhere on Earth
autumn begins in the northern hemisphere
spring begins in the southern hemisphere
123
When is the March equinox?
March 20 or 21
124
What happens in the March equinox?
the north end of earth's rotation axis leans along earth's orbit
there are about 12 hours of daylight and 12 hours of darkness everywhere on Earth
spring begins in the northern hemisphere
autumn begins in the southern hemisphere
125
When is the June solstice?
June 20 or 21
126
What happens in the June solstice?
the north end of Earth's rotation axis is toward the sun
days in the northern hemisphere are longest and nights are shortest, summer begins
days in the southern hemisphere are shorts and nights are longest, winter begins
127
Earth travels around...
the sun
128
Earth's rotational axis always points in the...
same direction in space
129
Why isn't the moon always full?
Because the Moon orbits Earth and reflects sunlight differently depending on its position. The full moon happens about once every 29.5 days.
130
Does moon emit light?
no
131
How are we able to see the moon?
The moon receives its light from the sun. The moon's surface reflects about 12% of the light from the sun.
132
While Earth is revolving around the sun, the moon is revolving around....
The Earth
133
The moon makes one revolution every...
27.3 days
134
One complete rotation of the moon takes...
27.3 days
135
Why does the same side of the moon always faces the Earth?
Because the moon makes one rotation for every revolution of Earth
136
What is the side of the moon that is always facing the Earth called?
The near side
137
What is the side of the moon that is not facing the Earth called?
The far side
138
Why does the moon appear to change shape?
Because as the Moon orbits Earth, we see different amounts of its sunlit side. The changing positions of the Moon, Earth, and Sun make the visible part of the Moon’s lit surface look like it’s changing shape, creating the moon phases
139
What is the length of a lunar phase cycle?
29.5
140
During waxing phases...
more of the moon's near side is lit each night
141
During the first quarter phase...
The moon's entire western half is lit.
142
During the full moon phase...
The moon's near side becomes completely lit
143
During waning phases...
less of the moon's near side is lit each night
144
During the third quarter phase...
The moon's entire eastern side is lit.
145
During the new moon phase...
The moon's near side is completely dark
146
What is a phase?
The portion of the moon or a planet reflecting light as seen from Earth is called a phase.
147
New moon position
The moon is positioned between the Sun and the Earth
148
Waxing crescent position
The moon has moved slightly in its orbit, revealing a small portion of its sunlit side.
149
First quarter position
The moon is at a 90 degree angle relative to the sun and earth.
150
Waxing gibbous position
The moon continues its orbit, increasing the visible illuminated portion
151
Full moon position
Earth is between the Sun and the moon
152
Third quarter position
The moon is at a 90 degree angle relative to the Earth and the sun, on the opposite side from the first quarter
153
Waxing crescent position
The moon is nearing its position between the Sun and earth
154
New moon visibility
The side facing Earth is dark,
making the Moon invisible to us.
155
Waxing crescent visibility
A thin crescent of light appears on
the right side, visible shortly after
sunset.
156
First quarter visibility
Half of the Moon's right side is
illuminated, visible from afternoon
to early night.
157
Waxing gibbous visibility
More than half is illuminated, but
it's not yet full; visible from late
afternoon to night.
158
Full moon visibility
The entire face of the Moon is
illuminated, visible all night from
sunset to sunrise.
159
Waning gibbous
More than half is still illuminated,
but it's decreasing; visible most of
the night.
160
Third quarter visibility
Half of the Moon's left side is
illuminated, visible from late night
to morning.
161
Waning crescent visibility
A thin crescent of light appears on
the left side, visible shortly before
162
What is the umbra?
The center, darker of the shadow where light is totally blocked.
163
What is a penumbra?
The lighter part of a shadow where light is partially blocked.
164
Solar eclipses can only occur during the...
new moon phase
165
What is a solar eclipse?
When the moon's shadow appears on the earth's surface
166
What is a lunar eclipse?
A lunar eclipse occurs when the moon moves into Earth's shadow
167
Lunar eclipse can only occur during a....
full moon phase
168
What is gravity?
gravity is the attractive force that exists between all objects that has mass
169
Gravity between 2 objects depends on...
mass and distance
170
The more mass either object has, or the closer they are together, the...
stronger the gravitational force
171
What is gravity's role in the formation of the stars?
Gravity pulls dust and gas together. As the material gathers, it heats up until nuclear fusion begins--that's how a star forms
172
What is the role of gravity in the formation of the solar system?
The solar system was formed from a rotating cloud of dust, ice and gas called a nebula. Gravity caused the cloud to collapse inward, because the cloud was still rotating after the collapse, it flattened into a disk, Gravity pulled gas and dust towards the center of the disk, forming the sun. Next, planets began to form as gravity pulled these small particles together.and formed the 8 planets. The left over larger particles formed the moons that orbit the sun, and asteroids and meteors and comets.
173
What are galaxies?
Galaxies are a huge collection of dust, gas, and stars held together.
174
What are groups of galaxies called?
clusters
175
Most clusters exist in larger structures called...
superclusters
176
What galaxy do we live in?
The milky way
177
How many stars in the milky way?
200 billion
178
The milky way is a member of the...
Local group
179
What are the three types of galaxies?
spiral, elliptical, irregular
