Newtonian World and Astrophysics Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are gravitational fields

A

A field created around any object with mass, extending all the way to infinity, but diminishing as the distance from the centre of mass of the object increases.

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

Gravitational field strength equation

A

g=F
m

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

Newton’s law of gravitation for the force between two point masses

A

F=- GMm
r^2

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

What is the value of G (gravitational constant)

A

6.67x10^-11

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

Gravitational field strength equation for a point mass

A

g=-GM
r^2

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

Kepler’s 1st Law of motion

A

The orbit of a planet is an ellipse with the Sun at one of the two foci

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

Keplers 2nd Law of planetary motion

A

A line segment connecting a planet to the sun sweeps out equal areas during equal intervals of time

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

Keplers 3rd Law of planetary motion

A

The square of the orbital period T of a planet is directly proportional to the cube of its average distance r from the sun

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

Aphelion

A

The furthest point from the Sun in an orbit

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

Perihelion

A

The closest point to the Sun in an orbit

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

Eccentricity

A

A measure of the elongation of an ellipse

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

Ellipse

A

An elongated ‘circle’ with two foci

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

What is the AU astronomical unit

A

This is the mean distance from the earth to the sun 1.50x10^11

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

Orbital Period equation

A

T^2= (4π^2) r^3
GM

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

What is a geostationary orbit

A

This is the orbit a geostationary satellite has and it remains in the same position relative to a spot on the earths surface, by orbiting in the direction of the Earth’s rotation over the equator with a period of 24 hours.

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

Uses of geostationary satellites

A

Communications, military, gps (global positioning system), weather and climate, scientific research

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

What is gravitational potential at a point

A

This is the work done in bringing unit mass from infinity to the point and it is zero at infinity

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

What is gravitational potential energy

A

This is the capacity for doing work as a result of an object’s position in a gravitational field

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

What is escape velocity

A

This is the minimum velocity at which an object has just enough energy to leave a specified gravitational field

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

Gravitational potential energy equation

A

Vg = -GM and Vg is directly proportional to 1/r
r

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

Gravitational potential energy equation

A

E= mVg = -GMm
r

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

What is the area under a force distance graph

A

Work done

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

What is the universe

A

This is everything that exists within space and time

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

Galaxy

A

This is a collection of stars and interstellar dust and gas bound together by their mutual gravitational force

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

Solar System

A

This is a planetary system consisting of a star and at least one planet in orbit around it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Planet

A

This is an object in orbit around a star with a mass large enough for its own gravity to give it a round shape that undergoes no fusion reactions and that has cleared its orbit of most other objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Comet

A

This is a small irregular body made of ice, dust and small pieces of rock in an (often highly eccentric elliptical) orbit around the sun- as they approach the sun, some comets develop spectacular tails

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Planetary Satellite

A

This is a body in orbit around a planet- it may be natural or artificial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Asteroid

A

This is a small rocky airless object that orbits the sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Dwarf Planet

A

This is a celestial body that orbits the sun , has enough mass to assume a nearly round shape but it has not cleared its orbit of other objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the Cosmological principle

A

This is the assumption that when viewed on a large enough scale, the Universe is homogenous (density is same everywhere) and isotopic (its the same in all directions), and the laws of physics are universal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is nebula

A

This is a cloud of dust and gas (mainly hydrogen), often many hundreds of times larger than our solar system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Astronomical Unit (AU)

A

This is the average distance from the earth to the sun 1.50x10^11m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Light-Year (ly)

A

This is the distance travelled by light in a vacuum in a time of one year, 9.46x10^16m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The parsec (pc)

A

This is the distance at which a radius of one AU subtends an angle of one arc second 3.09x10^16m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Distance of a nearby star

A

1
Parallax angle (arc seconds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a white dwarf

A

A very dense star formed from the core of a red giant, in which no fusion occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is a red giant

A

This is an expanding star at the end of its life, with an inert core in which fusion no longer takes place but does in the shell around the core with lighter elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is electron degeneracy pressure

A

This is created by electrons in the core of a collapsing star due to the fact 2 electrons cannot exist in the same energy state (Pauli exclusion).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is Chandrasekhar limit

A

This is the mass of a star’s core beneath which the electron degeneracy pressure is sufficient to prevent gravitational collapse, 1.44 solar masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Characteristics of a neutron star

A

This is formed if the mass of the core is greater than 1.44 Ms as the gravitational collapse continues. Almost entirely made up of neutrons and can be very small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Characteristics of a black hole

A

The remnant core of a massive star after it has gone supernova and the core has collapsed so far that in order to escape it, an object would need a velocity greater than the speed of light and therefore nothing can escape. Vary in mass

43
Q

Emission line spectra

A

each element produces a unique emission line spectrum because of its unique set of energy levels

44
Q

Continuous spectra

A

All visible frequencies or wavelengths are present. The atoms of a heated solid metal will produce this type of spectrum

45
Q

Absorption line spectra

A

This type of spectrum has series of dark spectral lines against the background of a continuous spectrum. The dark lines have exactly the same wavelengths as the bright emission spectra lines for the same gas atoms

46
Q

What is a diffraction grating

A

This is an optimal component with regularly spaced slits or lines that diffract and split light into beams or different colour travelling in different directions

47
Q

Equation for spectra

A

dsinθ =n λ

48
Q

Stefan’s law

A

This states that the total power radiated per unit surface area of a black body is directly proportional to the fourth power of the absolute temperature of the black body.

49
Q

Excited definition

A

This means containing an electron or electrons that have absorbed energy and have been boosted into a higher energy level

50
Q

Red supergiant

A

This is a huge star in the last stages of its life before it ‘explodes’ in a supernova.

51
Q

What is luminosity

A

This is the total radiant power output of a star

52
Q

Black body

A

This is an idealised object that absorbs all the electromagnetic radiation incident on it and when in thermal equilibrium, emits a distribution of wavelengths at a specific temperature

53
Q

Kinetic theory of gases model definition and its assumptions

A

This is a model used to describe the behaviour of the atoms or molecules in an ideal gas. Assumptions: large number of molecules in random, rapid motion. Particles occupy negligible volume compared to volume of gas. There are negligible forces between particles except during collisions. All collisions are perfectly elastic and the time of the collisions is negligible compared to the time between the collisions.

54
Q

Pressure in terms of Newtonian theory

A

3rd law shows that the total pressure on the wall is equal to the sum of the force of each collision between atoms in the gas and the wall, and it’s area for a container

55
Q

Number of particles N=

A

n x Na
(Number of moles) x Avogadro’s constant (6.02x1023)

56
Q

The molar mass definition

A

Mass of one mole of the substance

57
Q

Mass of a sample =

A

Number of moles x Molar Mass
m= n x M

58
Q

Boyle’s law

A

For a fixed mass of gas at constant temperature p is inversely proportional to V. pV is a constant

59
Q

What is oscillating motion

A

Oscillating motion is repetitive motion of an object around its equilibrium position

60
Q

Simple harmonic motion

A

Oscillating motion for which the acceleration of the object is directly proportional to its displacement and is directed towards some fixed point

61
Q

Isochronous oscillator

A

This has the same period regardless of amplitude. The period of an isochronous oscillator is independent of its amplitude.

62
Q

Displacement

A

The distance from equilibrium position

63
Q

Amplitude

A

The maximum displacement from the equilibrium position

64
Q

Period

A

The time taken to complete one full oscillation

65
Q

Frequency

A

The number of complete oscillations per unit time

66
Q

Phase difference

A

The difference in displacement between two oscillating objects or the displacement of an oscillating object at different times

67
Q

Damping

A

This is the process by which the amplitude of the oscillations decreases over time when an external force acts on it

68
Q

Light damping and example

A

Occurs naturally and the amplitude decreases exponentially with the period almost unchanged

69
Q

Heavy damping and example

A

Period increases and the amplitude decreases dramatically. Pendulum oscillating in water

70
Q

Critical or very heavy damping and example

A

The object stops before one oscillation is completed. Pendulum oscillating in treacle

71
Q

Free oscillation

A

The motion of a mechanical system displaced from its equilibrium position and then allowed to oscillate without any external factors

72
Q

Forced oscillation

A

An oscillation in which a periodic driver force is applied to an oscillator

73
Q

Driving frequency

A

The frequency with which the periodic driver force is applied to a system in forced oscillation

74
Q

Natural frequency

A

The frequency of a free oscillation

75
Q

Resonance

A

The increase in amplitude of a forced oscillation when the driving frequency matches the natural frequency of the oscillating system. If not damped the system may break.

76
Q

Practical example of a forced oscillation

A

Suspension systems in cars and bikes absorbing the energy from bumps

77
Q

Practical example of resonance

A

Many musical instruments resonate to produce louder notes. Microwaves cause water molecules to resonate. Tuning circuits in radios use resonance effects to select the correct frequency radio wave signal .

78
Q

Triple point

A

For a given substance, one specific temperature and pressure at which all three phases (solid,liquid and gas) of that substance can exist in thermodynamic equilibrium

79
Q

Temperature in kelvin

A

Temperature in degrees + 273

80
Q

Absolute zero

A

The lowest possible temperature, the temperature at which substances have minimum internal energy

81
Q

Thermal equilibrium

A

A state in which there is no net flow of thermal energy between the objects involved. Objects in thermal equilibrium must be at the same temperature.

82
Q

Kinetic model

A

The kinetic model describes all substances as made of atoms, ions or molecules, arranged differently depending on the phase of the substance

83
Q

Brownian motion

A

This is the continuous random motion of small particles suspended in a fluid

84
Q

Solids

A

Fixed volume, fixed shape, strong electrostatic forces of attraction between particles, low kinetic energy, high density, negligible compressibility, arranged in a regular 3-dimensional structure packed closely together, can vibrate but cannot move out of their positions in the structure

85
Q

Liquids

A

Fixed volume, not fixed shape, intermediate kinetic energy, low density, very low compressibility, weak electrostatic forces of attraction between the particles, particles free to move around but still very close together, this flows easily and can change position

86
Q

Gases

A

Volume not fixed, shape not fixed, high kinetic energy, very low density, high compressibility, negligible electrostatic forces between particles almost none, particles free to move around and far apart from each other, they move quickly in straight lines colliding with the walls of the container and each other

87
Q

Internal energy

A

The internal energy of a substance is defined as the sum of the random distribution of kinetic and potential energies associated with the molecules of a system

88
Q

Specific heat capacity

A

The specific heat capacity of a substance is defined as the energy required per unit mass to change the temperature by 1 kelvin or degrees Celsius

89
Q

Specific latent heat

A

This specific latent heat of a substance is defined as the energy required to change the phase per unit mass while at a constant temperature

90
Q

Specific latent heat of fusion Lf

A

When the substance changes from solid to liquid phase

91
Q

Specific latent heat of vaporisation

A

When the substance changes from liquid to gas

92
Q

Absolute scale of temperature

A

A scale for measuring temperature based on absolute zero and the triple point of pure water

93
Q

Doppler effect

A

This is the change in the frequency and wavelength of waves received from an object moving relative to an observer compared with what would be observed without relative motion.

94
Q

Hubble’s law

A

The recessional speed of a galaxy is almost directly proportional to its distance from the earth

95
Q

Big Bang Theory

A

This is the theory that at a moment in the past all the matter in the Universe was contained in a singularity, the beginning of space and time, that expanded rapidly outwards. The region was much hotter and denser that it is today.

96
Q

Blue shift

A

The shortening of observed wavelength that occurs when a wave source is moving towards the observer- in astronomy, if a galaxy is moving towards the earth, the absorption lines in its spectrum will be blue shifted, that is, moved towards the blue end of the spectrum.

97
Q

Red shift

A

The lengthening of observed wavelength that occurs when an object is moving away from the observer - in astronomy, if a galaxy is moving away from the earth (receding), the absorption lines in its spectrum will be red-shifted

98
Q

Stellar parallax

A

A technique used to determine the distance to stars that are relatively close to the earth (less than 100pc) by comparing their apparent positions against distant stars at time 6 months apart

99
Q

Planetary nebula

A

The outer layers of a red giant that have drifted off into space, leaving the hot core behind at the centre as a white dwarf

100
Q

Wien’s displacement law

A

The peak wavelength λmax at which the intensity of radiation from a black body is a maximum is inversely proportional to the absolute temperature T of the black body

101
Q

Hubble constant Ho

A

The gradient of a line of best fit for a plot of recessional speed against distance from Earth of other galaxies

102
Q

Estimation for the age of the universe

A

t is proportional to Ho^-1

103
Q

Current ideas of the universe

A

Universe is made up of dark energy, dark matter and a small percentage of ordinary matter

104
Q

Evolution of the universe after the Big Bang to the present

A

Time and space are created. The universe is a singularity- it is infinitely dense and hot.