Brainscape's Knowledge GenomeTM

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


See full index

advanced higher physics > Astrophysics > Flashcards

Astrophysics Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What is 1 light year equal to in meters? (Astrophysics)

A

9.46 x 10^15

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

What is the gravitational field strength on the surface of Earth? (Astrophysics)

A

9.8Nkg-1

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

What is the gravitational field strength on the surface of Mars? (Astrophysics)

A

3.7Nkg-1

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

What is the gravitational field strength on the surface of the Moon? (Astrophysics)

A

1.6Nkg-1

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

What is the gravitational field strength on the surface of the Sun? (Astrophysics)

A

270Nkg-1

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

What is meant by gravitational field strength? (Astrophysics)

A

The gravitational force per unit mass

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

What is meant by Gravitational potential of a point in Space? (Astrophysics)

A

The work done in moving unit mass from infinity to that point.

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

What is the result of a conservative field? (Astrophysics)

A

The energy required to move mass is dependent on the path taken.

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

What is a gravitational potential ‘well’ (Astrophysics)

A

A way of conceptualising the gravitational potential field in a body such as a planet.

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

What happens as a gravitational potential well gets deeper? (Astrophysics)

A

More energy will be required by an object trying to escape it.

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

What provides a centripetal force on a satellite when held in orbit around the Earth? (Astrophysics)

A

Earth’s gravitational force

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

What is escape velocity? (Astrophysics)

A

The minimum velocity required by a mass, m, to just escape from a planet’s gravitational field and reach infinity with zero velocity and zero kinetic energy.

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

Deriving Escape Velocity (Astrophysics)

A

Ek + Ep = 0

1/2 mv^2 + (-GMm / r ) = 0

1/2 mv^2 = GMm / r

v^2 = 2GM / r

Vesc = (sqrt.) 2GM / r

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

What is the Equivalence Principle? (Astrophysics)

A

Gravity pulling in one direction is equivalent to acceleration in the other.

That is, there is no way to distinguish between the effects on an observer of a uniform gravitational field and of a constant acceleration.

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

How does time run when there is a stronger gravitational field? (Astrophysics)

A

Slower

  • Moving clocks run slow, high clocks run fast *
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Curvature of Spacetime (Astrophysics)

A

A massive object like a star warps time and space through its gravity.

The larger the mass, the more spacetime curvature takes place.

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

Explain the rubber sheet analogy in relation to Curvature of Spacetime (Astrophysics)

A
  • Matter tells space how to curve
  • Curved space tells matter how to move

-The heavier the object the deeper the resulting gravitational well.

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

What is Evidence for the warping of Spacetime? (Astrophysics)

A

Gravitational time dilation

Gravitational Lensing

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

What is Gravitational time dilation? (Astrophysics)

A

Where time passes more quickly because the force of gravity is weaker.

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

What is Gravitational lensing? (Astrophysics)

A

The bending of light from a distant light source due to the presence of a large mass.

21
Q

What happens when Mercury orbits around the Sun? (Astrophysics)

A

Shifts slightly in its elliptical path every orbit.

22
Q

Why is Mercury’s orbit altered when orbiting the Sun? (Astrophysics)

A

The disturbance of spacetime by the Sun’s mass.

23
Q

What is a world line? (Astrophysics)

A

A curve in spacetime joining the positions of a particle throughout its existence.

:. Defines the position of an object in 3 dimensions (x, y and z) and 4th dimension of time (t).

24
Q

What does the z-axis of a spacetime diagram represent? (Astrophysics)

A

Time

25
Q

How is an object travelling at a constant speed represented on a spacetime diagram? (Astrophysics)

A

A straight horizontal line

26
Q

How is an object which is accelerating represented on a spacetime diagram? (Astrophysics)

A

A curved line outwards.

27
Q

How is an object which is not moving represented on a spacetime diagram? (Astrophysics)

A

A straight vertical line.

28
Q

What is a black hole? (Astrophysics)

A

A region in space where the pull of gravity is so great that nothing, not even light, can escape its pull.

29
Q

Is the escape velocity from close to a black hole greater or less than the speed of light? (Astrophysics)

A

Greater than.

30
Q

Where may supermassive black holes be found according to evidence? (Astrophysics)

A

The centre of large galaxies.

31
Q

Is light able to escape from the gravitational pull after a star has collapsed past the event horizon. (Astrophysics)

A

No

32
Q

What is the singularity of a black hole? (Astrophysics)

A

The centre point of a black hole where gravity becomes infinite

33
Q

What is the Schwarzschild radius? (Astrophysics)

A

The distance from the singularity to the event horizon.

34
Q

What are ways that you can detect black holes? (Astrophysics)

A
  • Emission of x-rays
  • Gravitational lensing
  • Binary x-ray systems
35
Q

What determines what colour a star will appear as? (Astrophysics)

A

The surface temperature.

  • Cooler the star, redder it will appear
  • Hotter the star, more blue it will appear
36
Q

What gives the total energy being emitted at all wavelengths by a black body? (Astrophysics)

A

The Stefan-Boltzmann Law.

37
Q

What is a black body? (Astrophysics)

A

A body that absorbs all EM radiation incident on it and also emits all wavelengths of EM radiation.

38
Q

What type of stars are the least massive? (Astrophysics)

A

Red dwarfs

39
Q

What type of stars are the most massive? (Astrophysics)

A

Blue giants

40
Q

What does the mass of a star determine (Astrophysics)

A

Its lifetime, and therefore its overall fate.

41
Q

What is the luminosity of a star (Astrophysics)

A

A measure of how bright it actually is, not how bright it appears to us on earth.

42
Q

What is the apparent brightness of a star? (Astrophysics)

A

A measure of how bright a stars appears on Earth.

43
Q

Formation of Stars (Astrophysics)

CGNHM

A
  • Huge clouds of gas and dust
  • Gravity causes clouds to shrink
  • Nuclear fusion occurs (hydrogen => helium by p-p chain)
  • Hydrostatic Equilibrium - When gravitational force is balanced by thermal pressure outwards
  • Main sequence.
44
Q

Low Mass Stars (Astrophysics)

A

Cloud of gas and dust => Main sequence => Red giant => White dwarf

45
Q

High Mass Stars (Astrophysics)

A

Cloud of gas and dust => Main sequence => Red supergiant => Supernova => Black hole (very high mass) OR Neutron star (high mass)

46
Q

What is a Charge Coupled device? (CCD) (Astrophysics)

A

A chip found behind the lens in a digital camera that stores images.
It is used to detect astronomical objects.

47
Q

What is an Inertial frame of reference? (Astrophysics)

A

A frame of reference in which an observer is not accelerating with respect to another.
That is, an observer will move at a constant speed with respect to another.

48
Q

What is a Non-Inertial frame of reference? (Astrophysics)

A

A frame of reference in which an observer is accelerating with respect to another.
That is, an observer will not move at a constant speed with respect to another.

49
Q

What does the bottom cone on a world line diagram represent (Astrophysics)

A

Observable past events

advanced higher physics (7 decks)

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