Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PT > Space > Flashcards

Space Flashcards

chap 24+25

1
Q

Gamma rays are produced during fusion in the Sun. How long does it take for the energy to reach the surface due to collisions?

A

100,000 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the temperature in the Sun’s core and surface?

A

core is 1.5x10^6 K (plasma, ionised gas)
surface is 5800 K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

At what distance does the Earth orbit the Sun?

A

150 million km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the solar mass and how much of it is apart of the total mass of the solar system?

A

2x10^30 kg
99.86%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How large is a light-year? What is it?

A

9.5x10^15 m, distance travelled by light in space in one year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is our second nearest star and how far?

A

Proxima Centauri, 4.2 light-years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How far is Pluto from the Sun?

A

40x further than what Earth is from the Sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How far is Proxima Centauri from the Sun?

A

7000x further than what Pluto is from the Sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How may stars in the Milky way?

A

2x10^11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How many galaxies make up the universe?

A

billions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is our closest galactic neighbour?

A

Canis Major Dwarf Galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is our closest spiral galaxy?

A

Andromeda galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

If a planet is further..(forces, speed, orbit)

A

experiences less gravitational force, more kinetic energy, smaller speed, larger orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

If a planet is heavy.. (field)

A

greater field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When are heavy elements produced in a life cycle of a star?

A

when a red supergiant explodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Countries in the Northern hemisphere

A

rays are more spread out on country, so colder and fewer daylight hours. Those closer to equator do not experience seasons because rays hit them at same angles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When do we see the Moon? How many days to orbit Earth?

A

light from the Sun is reflected from the Moon’s surface, 27.5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define planet and minor planet.

A

a (large spherical) object which orbits the Sun…

planet: without a similar object close to it
minor: but is not large or far enough from other objects to be defined as a planet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where are most asteroids found?

A

In the asteroid belt between Mars and Jupiter. They are made of left-over pieces of rock.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define comet. Where does the tail point?

A

a ball of ice, dust and gas which orbits the Sun in a highly elliptical orbit. Away from the Sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain, in terms of energy transfers, why the SPEED of Pluto varies in this way.

A

 gravitational (potential) energy (GPE) transfers to kinetic energy (KE) or vice versa
 KE transfers to GPE from X to Y AND GPE transfers to KE from Y to X
 speed decreases as KE decreases
 most GPE at Y OR least GPE at X
 total (of GPE + KE) energy is constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why are orbits elliptical?

A

An object is carried by its momentum from the explosive start of the universe. As it passes the Sun, the force of the Sun pulls it in towards the Sun.

The force causes it to accelerate. The object’s kinetic energy carries slightly further out to the furthest point of the orbit. Slows down and is pulled in again.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The shape of the orbit of the comet from P to Q is circular, with the Sun at its centre.
State and explain the changes, if any, in the speed and in the velocity of the comet as it
moves from P to Q.

A

(speed) is constant, as the distance from the Sun is constant

(velocity) is (constantly) changing
as the direction of motion (of the comet) is (always) changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What to remember for moon phases?

A

middle is white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

State what the phases of the Moon indicate about the motion of the Moon.

A

the Moon orbits the Earth,
the duration of the Moon’s orbit is (approximately) one month 27.5 days

26
Q

What is redshift?

A

a difference, an increase, in the observed wavelength of electromagnetic radiation from a star or galaxy because it is moving away from us

(shifted towards the red end, the longer wavelengths, and so are stretched)

27
Q

State one method for estimating the distance d of a distant galaxy from the Earth

A

using the brightness of a supernova in the (distant) galaxy

28
Q

Explain how, according to the Big Bang Theory, (hubble’s constant formula)
represents the age of the Universe.

A

according to the Big Bang Theory, all matter originated from one point and time in space

if the distance a galaxy has travelled is d and the speed it has been moving at is v

the time it has been moving = vd  / (the equation is) AND this is the time from the Big Bang / start of the Universe

29
Q

A distant star explodes as a supernova.
Which statement is not correct?
A The exploding supernova forms a planetary nebula.
B The distant star is large when compared with the Sun.
C The supernova releases heavy elements into space.
D The supernova leaves behind a neutron star or a black hole

A

A, radiation pressure blows the outer shell away to create a planetary nebula (small star)

30
Q

Graph P and graph Q show how the speed of these distant galaxies changes as their distance from the Earth increases.
In which row are the statements about the Hubble constant and about the age of the Universe
correct?

A

Hubble constant: v/d graph
Universe age: d/v graph

31
Q

How were the inner, small, rocky planets formed?

A

Planets are formed from materials not pulled into the Sun.

The spinning motion of dust and gas formed an accretion disc, a rotating disc of matter formed by accretion.

Gravity pulled the dust and gas together which joined to form rocks, then larger rocks. This process is accretion, the coming together of matter under the influence of gravity to form larger bodies.

32
Q

Explain how the Sun was formed.

A

Planets could have been formed at the same time as the Sun.

The Solar System began as a huge swirling ball of gas and dust, a nebula. Most of the gas was hydrogen.

The other elements were formed by fusion in other stars which exploded by the end of their lifecycle, sending their contents out into clouds of interstellar gas.

As gravity pulled this mass together, the centre formed a star.

33
Q

How were the gas giants formed? (material gorl)

A

The intense heat forced some of the lighter materials further away and formed the four outer planets.

34
Q

What elements is the Sun made up of?

A

75% hydrogen, 24% helium, 1% others such as oxygen and carbon

35
Q

What energies does the Sun radiate?

A

50% infrared, 40% visible light and 10% ultraviolet (ozone layer absorbs most ultraviolet)

36
Q

What nuclear reaction is the Sun and other stable stars powered by?

A

fusion of hydrogen nuclei into helium nuclei by nuclear fusion

37
Q

What is a stable star? (Remember..)

A

a star that is not collapsing or expanding because the inward force of gravity is balanced by radiation pressure which pushes outwards

38
Q

What is a protostar? (Remember)

A

a very young star still gathering mass from its parent molecular cloud

39
Q

(Just the beginning part)

How is a star formed?

A

Form from clouds of interstellar (occupies space between stars) gas and dust that contain hydrogen called molecular clouds. These are cold and dense enough to collapse and form stars.

40
Q

How far is the Orion Nebula in the Milky Way from us?

A

1350 light-years

41
Q

Explain in detail, the formation of stars.

A

Collapses due to gravitational attraction, starting a series of energy transfers.

Forces of gravity pulls hydrogen gas molecules together. G.P.E is transferred to ke.

As molecules collide, ke is transferred to thermal energy.

The clump contracts into a spinning sphere of super hot gas, a protostar.

Continues to grow by pulling in more material from the molecular cloud. Mass determines its fate.

42
Q

What is radiation pressure?

A

The outward force due to the high temp of the star. Higher core temp= higher pressure. (Makes a star expand)

43
Q

Explain the lifecycle of a star of less than 8 solar masses. (until comparsion)

A

Begins life as a protostar. When it runs out of hydrogen, reactions slow down, there is reduced radiation pressure and the star contracts.

gpe -> thermal. Temp of core and outer shell of helium decreases.

Core becomes hot enough for fusion of helium. There is a bigger electrostatic repulsion between helium nuclei, charge of +2 instead of +1 for hydrogen.

44
Q

How old is the Sun? (more info) (when does it become a red giant and dwarf star?)

A

4.6 billion years old, half-way through its time being a main sequence star (stable star burning hydrogen in it core)

When it expands beyond Earth’s orbit, it will become a red giant. When it becomes a dwarf star, it shrinks to 1% of its size size of Earth

45
Q

Explain the lifecycle of a star of less than 8 solar masses. (after comparsion) All about the outer.

A

Heating the outer shell causes it to expand and cool, turning the star red. It has become a red giant.

Eventually, the core collapses into a white dwarf star. Not hot enough to fuse heavier elements, so it cools to become a black dwarf star.

Radiation pressure blows the outer shell away to create a planetary nebula.

46
Q

Explain the life cycle of a star exceeding 8 solar masses. (until the end of the shells part, red super giant)

A

Also begins as a protostar before entering the stable star period. Core gets so hot, nuclei of heavier elements can fuse. Lighter elements fusion continues in further shells. Outer shell expands to red supergiant.

47
Q

Explain the rest of the life cycle of a star of more than 8 solar masses. (after shells part)

A

Fuel runs out, star collapses and explodes as a supernova. Enough energy to create heavier than iron elements and push them into space as a nebula, along with lighter elements including hydrogen.

Mass of its core determines its fate. Less than 3, neutron star forms. Gravity so strong, protons and electrons forced together. More than 3, black hole, continues collapsing until iit is so dense that light cannot escape.

48
Q

Which stars spend less time as a main sequence star? (bigger muscles and strong..)

A

More massive stars, because higher core temp and use up fuel more quickly

49
Q

What did the Big Bang create?

A

hydrogen, helium, trace of lithium (stars have prod the rest

50
Q

How is the absorption spectrum formed?

A

Dark lines are the wavelengths of light missing from sunlight. Cool gas in the Sun’s atmosphere absorbs them and forms the absorption spectrum.

51
Q

How do astronomers work out the elements in a star?

A

Each element has a unique set of lines, the spectral fingerprint.

52
Q

What happens in Doppler effect?

A

Vehicle moves forward= shorter wavelength= higher pitch

At the back wavelength increases.

53
Q

What is the Big Bang theory? + (what is it doing ever since?) + (What happened before to neutral atoms?)

A

The Universe was created at a single point 13.8 billion years ago and has been expanding and cooling ever since. (was hot and dense, neutral atoms could not forms, instantly ionise)

54
Q

What is Hubble’s Law?

A

how fast distant galaxies are moving away from Earth with a speed, v, that is proportional to their distance, d, from Earth. v=Hod (2.2x10^-18)

55
Q

What is Hubble’s constant?

A

slope of a garph of galaxy speed against distance

56
Q

What is Hubble’s time?

A

inverse of Hubble constant, which gives the estimate of the Universe’s age

57
Q

State when cosmic microwave background radiation (CMBR) was formed and where we
detect it coming from.

A

It is a wavelength of light in the microwave region . Shortly after the Big Bang, when the universe was formed. Found all points in space.

Expansion of Universe caused wavelength of light to redshift over time.

Two scientists heard noise coming from their telescope, it turned out to be microwave radiation.

58
Q

Why can you not see far into light? When did the universe cool down?

A

Was continuously scattered by charged particles, ions and elecctrons. It’s scattered into fog.
When size of Milky way, cooled down so neutral atoms formed.

59
Q

How can distance to a galaxy be determined using a type 1a supernova.

A

By recording how bright it is and how it appears to be.

60
Q

When do type1a supernova occur?

A

When a white dwarf star in a binary system pulls in material from its companion until it reaches a certain mass and explodes.

PT (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions