Exam 2
What is the absolute magnitude of our Sun? +4.8 -4.6 -1.4 -23.0 +9.4
+4.8
In what range of masses are most stars found? .01 to 100 solar masses .1 to 2 solar masses 1 to 3 solar masses .1 to 100 solar masses Stars can have any mass.
.1 to 100 solar masses
Procyon lies about 13 light-years distant, thus its parallax is about 1.3". 0.40". 0.65". 0.25". 0.01".
0.25"
On average, how long does it take for photons produced by nuclear fusion to escape the Sun? A. 1 year B. 1000 years C. 1,000,000 years D. 1,000,000,000 years
1,000,000 years
The speed of light is 3.00 × 108 m/s. If 2.00 kg of mass is converted to energy, how much energy will be produced? 1.80 × 1017 J 9.00 × 1016 J 6.00 × 104 J 1.50 × 108 J 6.00 × 108 J
1.80 × 1017 J
If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be twice as strong. one-quarter as strong. one-third as strong. half as strong.
1/4 as strong
The temperature of the layer of gas that produces the visible light of the Sun is 15 million K 300,000 K 3,500 K 12,300 K 5,800 K
5800K
The moons of the jovian planets formed by which two processes? Accretion and capture Collisions and differentiation Differentiation and capture Capture and collisions Accretion and collisions
Accretion and Capture
What direction to the planets appear to orbit the Sun when viewed from far above the Earth's north pole? A. All planets orbit clockwise B. Some planets orbit clockwise, some counter-clockwise C. All planets orbit counter-clockwise
All planets orbit counter-clockwise
How would the solar system be different if the solar nebula had cooled with a temperature half its current value? A. Jovian planets would have formed closer to the Sun B. There would be no asteroids C. There would be no comets D. Terrestrial planets would be larger
Jovian planets would have formed closer to the Sun
the law of universal gravitation was developed by
Newton
Which of the following energy sources powers the Sun? A. Chemical energy B. Gravitational contraction C. Nuclear fusion D. Something else
Nuclear fusion
True/False: the photosphere is about 100 times the diameter of the Earth
True
Energy move through the Sun's ___ ___ by means of the rising of hot gas and falling of cooler gas
convection zone
Rank the following layers of the Sun based on their temperature, from highest to lowest. core radiation zone photosphere convective zone
core radiation zone convective zone photosphere As you have correctly answered, the Sun's temperature drops from the core to the surface, which is the photosphere. Notice that this part did not include the chromosphere and corona as choices, because their temperatures are surprisingly high, despite their very low densities
we can see the Sun's __ most easily during total solar eclipses
corona
Earth orbits in the shape of a/an ___ around the Sun
ellipse
Earth is located at one __ of the Moon's orbit
focus
Which of the following energy sources powers the Sun? A. Chemical energy B. Gravitational contraction C. Nuclear fusion D. Something else`
nuclear fusion
according to Kepler's second law, Pluto will be traveling fastest around the Sun when at ___
perihelion
All the photons produced in the Sun's core have been absorbed by the outer edge of what region of the Sun? radiation zone core convection zone photosphere
radiation zone; The key here is "outer edge." The radiation zone is mostly transparent, but by the time you get to its outer edge, atoms are capable of absorbing light. This causes the transition between radiation and convection.
due to its mmuch higher density, water heated to 80 degrees (Celsius) contains more ___ energy than air at the same temp
thermal
Why do sunspots appear dark? They have lower rotation rates. They are storm systems like those on the jovian planets. They have lower densities. They have lower temperatures.
they have lower temperatures; stefan's law states that the brightness of an obj is directly related to its temp raised to the fourth power
T/F: The orbits of most of the planets in our solar system have eccentricities close to zero.
true
A large cloud in space has a radius of 100,000 AU and a rotational speed of 10 km/s. The cloud is collapsing due to its own gravity. What size will the cloud be when it has a rotational velocity of 1000 km/s? A. 10,000 AU B. 1000 AU C. 100 AU D. 10 AU
1000 AU // Conservation of angular momentum! Mass x velocity x radius = constant
A large cloud in space has a radius of 100,000 AU and a rotational speed of 10 km/s. The cloud is collapsing due to its own gravity. What size will the cloud be when it has a rotational velocity of 1000 km/s? A. 10,000 AU B. 1000 AU C. 100 AU D. 10 AU
1000AU
Let's think about Eta Cancri again. Recall that the two stars had the same surface temperature, but their luminosities differed by a factor of 106. How much bigger is Eta Cancri A than Eta Cancri B? A. 10 times B. 100 times C. 1000 times D. 10,000 times
1000times
How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it would be if Earth were at 10AU, in the orbit of Saturn? 5X 25X 10X 100X 250X
100X
The sunspot cycle is the rise and fall of the number of sunspots on the surface of the Sun. How long does the sunspot cycle typically last A. 32 days B. 11 years C. 22 years D. 20,000 years
11 yrs
As the Sun rotates, an individual sunspot can be tracked across its face. From eastern to western limb, this takes about a month. 5.5 years. two weeks. 12 hours. a week.
2 weeks
In a visual binary system with circular orbits, if in 20 years the two stars' position angles have shifted by 30 degrees, the pair's period must be 60 years. 240 years. 90 years. 120 years. 360 years.
240 yrs
Jupiter is located at a distance of 5.2 AU from the Sun. How does the brightness of the Sun viewed from Jupiter compare to that observed at Earth? A. 25 times less bright B. The brightness is the same because the Sun's luminosity is constant C. 5 times less bright D. 25 times more bright`
25 times less bright
The brightest star in the sky, Sirius, has a parallactic angle of 0.3 arcsecs. How far away is Sirius? A. 0.3 parsecs B. 0.3 light years C. 3 parsecs D. 3 light years
3 pc
If you were to throw a ball from the highest levels of the Cathedral of Learning, how fast would it be moving after 3 seconds? You can ignore air resistance. A. 10 m/s B. 30 m/s C. 90 m/s D. There isn't enough information to tell
30 m/s
Pollux, the brightest star in the constellation Gemini, has a parallactic angle of 0.1 arcsecs. How far away is Pollux? A. 3.3 parsecs B. 3.3 light years C. 33 parsecs D. 33 light years`
33 ly
Halley's comet has a perihelion distance of 0.6 AU and an orbital period of 76 years. What is the aphelion distance of Halley's comet from the Sun? Express your answer using two significant figures. da =
35 AU
The Sun has sufficient hydrogen to continue fusing into helium for how much longer? 10 billion years 1 billion years 5 billion years 100 million years
5 billion years
A nearby star has a parallax of 0.2 arc seconds. What is its distance? 5 parsecs 50 parsecs .2 parsec .5 parsec .1 parsec
5 parsecs
Standing on the surface of the Earth you drop a rock down a well and it falls for 5 seconds before hitting the bottom. How fast is it moving when it hits the bottom of the well? Neglect air resistance. It depends on how heavy it is. 50 m/s 15 m/s 10 m/s It depends on what shape it is.
50 m/s
Find Earth's approximate mass from the fact that the Moon orbits Earth in an average time of 27.3 days at an average distance of 384,000 kilometers. (Hint: The Moon's mass is only about 1/80 of Earth's.) Express your answer to two significant figures and include the appropriate units. MEarth =
6.0×10e24 kg
How much energy is released by the fusion of 4 protons into 1 helium nucleus? A. About 10-11 Joules B. About 10-12 Joules C. About 10-13 Joules D. About 10-14 Joules
About 10-12 Joules
If a star is less than 10 parsecs from us, what can we say about how its apparent and absolute magnitudes compare? Absolute magnitude will be the larger number. They will be the same number. Apparent magnitude will be the larger number. More information is needed to make a judgement.
Absolute magnitude will be the larger number.//Since larger numbers are dimmer in the magnitude system, this would mean that the star looks brighter than it actually is, indicating it is closer than 10 parsecs
Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise. All the planets orbit counterclockwise around the Sun. The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise. All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction.
All the planets orbit counterclockwise around the Sun.
Two stars, Altair and Minar, have the same apparent brightness. However, Altair is twice as far away as Minar. How do their luminosities compare? A. They have the same luminosity because they have the same brightness B. Altair is twice as luminous as Minar C. Minar is four times as luminous as Altair D. Altair is four times as luminous as Minar
Altair is four times as luminous as Minar
Where are most asteroids found in the solar system? A. Between the Sun and Mercury B. Beyond the orbit of Neptune C. In the Oort Cloud D. Between Mars and Jupiter
Between Mars and Jupiter
The Kuiper Belt is found where in the solar system? Among the orbits of the terrestrial planets Sixty degrees ahead or behind Jupiter Between the orbits of Jupiter and Uranus Beyond the orbit of Neptune Between the orbits of Mars and Jupiter
Beyond the orbit of Neptune
Where in the solar system is the Kuiper Belt located? A. Between the Sun and Mercury B. Beyond the orbit of Neptune C. In the Oort Cloud D. Between Mars and Jupiter
Beyond the orbit of Neptune
Which of the following layers of the Sun can be seen with some type of telescope? Consider all forms of light, but do not consider neutrinos or other particles. Select all that apply. chromosphere photosphere core corona convection zone radiation zone
Chromosphere Photosphere Corona The photosphere can be seen with visible-light telescopes, while the chromosphere is most easily observed with ultraviolet telescopes and the corona with X-ray telescopes.
By what mechanism does solar energy reach the Sun's photosphere from the layer just underneath it? Conduction Ionization Differentiation Radiation Convection
Convection
In which of the following layer(s) of the Sun does nuclear fusion occur? Select all that apply. convection zone core radiation zone corona photosphere chromosphere
Core Nuclear fusion occurs only in the core of the Sun, where the temperatures, pressures, and densities are highest.
Which of the following is the correct list of regions of the Sun in descending order of temperature? A. Photosphere, convection zone, radiation zone, core B. Core, radiation zone, convection zone, photosphere C. Core, convection zone, photosphere, radiation zone D. Radiation zone, photosphere, convection zone, core
Core, radiation zone, convection zone, photosphere
In comparing first magnitude Deneb with second magnitude Polaris, we find that.... Polaris is really 100 times brighter than nearby Deneb. Deneb is really much closer than Polaris. Deneb must be much hotter than Polaris. Deneb appears 2.5 times brighter to us than does Polaris. Polaris is in reality much more luminous.
Deneb appears 2.5 times brighter to us than does Polaris.
What observation and physical principle could you use to determine the mass of the Sun? A. Measure the angular size of the Sun, determine its volume then multiple by the mass of a hydrogen atom B. Determine the radius of Earth's orbit, then use Kepler's 3rd Law C. Measure the acceleration of the Earth, then use Newton's Law of gravity D. Determine the size of an astronomical unit, then use Newton's generalized version of Kepler's Third Law
Determine the size of an astronomical unit, then use Newton's generalized version of Kepler's Third Law
What would happen to the orbits of each of the planets if the force of gravity was suddenly "turned off"? Nothing; each would continue to orbit the Sun. Each would slowly spiral away from the Sun. Each would move in the opposite direction from the Sun. Each would fall into the Sun. Each would move off in a different straight line.
Each would move off in a different straight line.
What energy transformation takes place in an incandescent (old school) light bulb? A. Chemical potential to Electrical to Thermal B. Electrical to Thermal to Radiative C. Electrical to Chemical potential to Radiative D. Electrical to Radiative
Electrical to Thermal to Radiative
True/False: Jupiter and the other jovian planets may have formed significantly closer to the Sun than their current orbits.
False
True/False: Within the frost line, planetesimals were composed entirely of rock, and outside the frost line, planetesimals were composed entirely of ice.
False
The solar spectrum is a good example of what kind of spectrum? continuum emission absorption none of the above
absorption; Continuous light from the hot, dense core of the Sun passes through the low-density atmosphere, producing an absorption spectrum.
How long does the sunspot cycle last, on average? About 76 years 365.25 days Between 25 and 35 days About 11 years About seven years
abt 11 yrs
On the H-R diagram, the Sun lies... at the top left. at the bottom right. about the middle of the main sequence. at the top right. at the bottom left.
abt the middle of the main sequence
A successful theory of the formation of the solar system must explain that all planets have elliptical orbits with high eccentricities. that the inner planets have more hydrogen and helium in their atmospheres than do the outer planets. all observed properties of the solar system. that all planets rotate in a prograde sense. the existence of the asteroid belt between Jupiter and Neptune.
all observed properties of the solar system
What happens when a solar nebula contracts? It heats up. It flattens out. It spins faster. All of the above None of the above
all of the above
Which of the following changes would cause the fusion rate in the Sun's core to increase? Check all that apply. an increase in the core temperature an increase in the core radius a decrease in the core temperature a decrease in the core radius
an increase in the core temperature a decrease in the core radius
According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at ____
aphelion
Planetary orbits are.. highly inclined to the ecliptic. have the Sun at their exact center. are evenly spaced throughout the solar system. are almost circular, with low eccentricities. are spaced more closely together as they get further from the Sun.
are almost circular, with low eccentricities.
On the H-R diagram, white dwarfs lie Sirius B and Procyon B lie at the lower right. at the top left. at the lower left. close to the Sun, near the center. at the top right.
at the lower left
On the H-R diagram, red supergiants like Betelgeuse lie at the bottom left. at the top left. at the bottom right. at the top right. They can't be plotted, for they are not main sequence.
at the top right
the tail of a comet always points... toward the Sun and disappears at perihelion. toward Earth and never varies. in the direction of the comet's motion. away from the Sun and becomes longest and brightest at perihelion. away from the Sun and disappears at perihelion.
away from the Sun and becomes longest and brightest at perihelion.
Where in the solar system does the asteroid belt lie? fig 6.5 p. 52-53 Between the orbits of Jupiter and Saturn Between the orbits of Earth and Mars Between the orbits of Venus and Earth Between the orbits of Mars and Jupiter None of the positions listed here is correct.
between the orbits of mars and jupiter
an apple contains ___ energy that your body can convert into other forms energy
chemical potential
Most of the Sun's ultraviolet light is emitted from the narrow layer called the ____ where temp increases with alt
chromosphere
Suppose an object is moving in a straight line at 50 miles/hr. According to Newton's first law of motion, the object will continually slow down but never quite come to a complete stop. eventually slow down and come to a stop. continue to move in the same way forever, no matter what happens. continue to move in the same way until it is acted upon by a force. continue to move in a straight line forever if it is in space, but slow and stop otherwise.
continue to move in the same way until it is acted upon by a force.
Nuclear fusion of hydrogen into helium occurs in the ___
core
In which of the following layer(s) of the Sun does nuclear fusion occur? Select all that apply. photosphere corona core chromosphere radiation zone convection zone
core Nuclear fusion occurs only in the core of the Sun, where the temperatures, pressures, and densities are highest.
Rank the following layers of the Sun based on the pressure within them, from highest to lowest. radiation zone photosphere core convective zone
core radiation zone convective zone photosphere As you have correctly answered, the Sun's pressure is highest at its center and drops steadily from the core to the surface. This fact reflects what we call gravitational equilibrium — the idea that the inward pull of gravity (or, equivalently, the weight of overlying layers bearing down) must at all points be balanced by the outward push of pressure.
Rank the layers of the Sun based on their density, from highest to lowest
core radiation zone convection zone photosphere chromosphere corona As your answer correctly indicates, the density of the Sun decreases from the center outward. The core has the highest density and the corona has the lowest density.
Listed following are the different layers of the Sun. Rank these layers based on their distance from the Sun's center, from greatest to least. chromosphere corona photosphere convection zone radiation zone core
corona chromosphere photosphere convection zone radiation zone core
According to Newton's Law of Universal Gravitation, if the Moon were three times further from Earth, the force by Earth on the Moon would increase by a factor of 9. decrease by a factor of 9. decrease by a factor of 3. increase by a factor of 3. stay the same.
decrease by a factor of 9
According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them _________. increases by a factor of 9 decreases by a factor of 9 increases by a factor of 3 decreases by a factor of 3
decreases, by a factor of 9
the extent to which Mars' orbit differs from a perfect circle is called its ____
eccentricity
Which type of binary can have their sizes measured directly by photometry? Eclipsing Virtual Spectroscopic Astrometric Visual
eclipsing
In a spectroscopic binary, if a pair shows a combined set of lines tonight, but a maximum split two nights later, its orbital period must be twelve days. eight days. one day. two days. four days.
eight days
What natural barrier tries to prevent two protons from combining? The strong nuclear force The weak nuclear force Electromagnetic repulsion Dark energy Antigravity
electromagnetic repulsion
The numbers of sunspots and their activity peak about every six months. 76 years. year. eleven years. 36 days.
eleven years
t/f: all known asteroids can be found in the asteroid belt
false
t/f: solar activity cannot disrupt communications on earth
false
As a rotating gas cloud contracts, it spins... faster due to an increase in angular momentum. faster due to conservation of angular momentum. slower due to a decrease in angular momentum. slower due to conservation of angular momentum. at a constant rate.
faster due to conservation of angular momentum.
If the Earth orbited the Sun at a distance of 0.5 AU, how would the force of gravity between the two compare to that at its actual location? A. The same B. Twice as small C. Four times as large D. Twice as large
four times as large// Recall that gravity is an inverse-square law F = GMm/ d^2
The pattern of rising hot gas cells all over the photosphere is called granulation. convective projections. prominences. sunspots. filaments.
granulation
Which of these are NOT associated with the active Sun? Sunspots Flares Aurora Prominences Granulation
granulation
an asteroid that is moving farther from the Sun is gaining ___ energy
gravitational potential
What forces are in balance so that the Sun remains a constant size? A. Gravity outwards, gas pressure inwards B. Electromagnetic force outwards, gravity inwards C. Gravity inwards, gas pressure outwards D. Rotational forces outwards, gravity inwards
gravity inwards, gas pressure outwards
Suppose you are in an elevator. As the elevator starts upward, its speed will increase. During this time when the elevator is moving upward with increasing speed, your weight will be __________. greater than your normal weight at rest equal to your normal weight at rest less than your normal weight at rest
greater than your normal weight at rest Increasing speed means acceleration, and when the elevator is accelerating upward you will feel a force pressing you to the floor, making your weight greater than your normal (at rest) weight.
the force of gravity between two objects... increases with the square of their masses, but decreases with the cube of their periods of orbit about the Sun. increases with the masses of the bodies, but decreases with the square of the distances between them. depends on the density, not the mass of the bodies. increases with the masses of the bodies, but decreases with their separations. depends on the temperature, density, and size of the bodies.
increases with the masses of the bodies, but decreases with the square of the distances between them
The outward pressure of hot gas in the Sun is increasing the Sun's diameter. weakens the magnetic field. is cooling the photosphere. is balanced by the inward gravitational pressure. is responsible for variations in the sunspot cycle.
is balanced by the inward gravitational pressure.
In the proton-proton cycle, the helium atom and neutrino have less mass than the original hydrogen. What happens to the "lost" mass? It is ejected into space. It is converted to energy. It is recycled back into hydrogen. It is transformed into electrons. Conservation of mass dictates no mass can be lost.
it is converted to energy
rapidly moving comets have more ___ energy than slowly moving ones
kinetic
Provided following are stages that occurred during the formation of our solar system. Rank these stages from left to right based on when they occurred, from first to last. condensation of solid particles clearing the solar nebula large cloud of gas and dust contraction of solar nebula accretion of planetesimals
large cloud of gas and dust contraction of solar nebula condensation of solid particles accretion of planetesimals clearing the solar nebula Once the solar wind helped clear away the remaining gas in the solar nebula, the era of planet formation was essentially over. Remember that all these stages occurred over a period of millions of years, ending about 4 1/2 billion years ago.
Suppose you are in an elevator that is moving upward. As the elevator nears the floor at which you will get off, its speed slows down. During this time when the elevator is moving upward with decreasing speed, your weight will be __________. greater than your normal weight at rest equal to your normal weight at rest less than your normal weight at rest
less than your normal weight at rest Even though the elevator is still moving upward, the fact that its speed is slowing means that the acceleration is downward; the situation is rather like that of a ball that is still on its way up after you throw it, even though it is being pulled downward with the acceleration of gravity. Because the acceleration of the elevator is downward, your weight is lower than normal.
What are the two most important intrinsic properties used to classify stars? Mass and age Distance and luminosity Distance and surface temperature Luminosity and surface temperature Distance and color
luminosity and surf temp
If you want to find a radius value for most stars, what must you first measure about the star? Luminosity and temperature Just the mass Apparent size and distance Temperature and distance
luminosity and temp// There is a definite relationship between luminosity, temperature and radius, so if you know two of these, you can find the third.
The Hertzsprung-Russell Diagram plots ________ against the spectral type or temperature. size or density brightness or apparent magnitude mass distance luminosity or absolute magnitude
luminosity or absolute magnitude
Absolute magnitude directly allows us to compute what intrinsic property of a star? Radius Luminosity Temperature Composition
luminosity, Absolute magnitude is an indicator of a star's intrinsic energy output, or luminosity.
Low-mass stars have much longer lifetimes than high-mass stars. Which stellar property is a direct cause of this difference? temperature composition luminosity radius
luminosity// The high luminosity of high-mass stars indicates that they are burning their fuel much faster than low-mass stars.
What is the common cause of sunspots, flares, and prominences? solar wind convection differential rotation magnetic fields
magnetic fields// involved in producing all three phenomena
What of the following is not a characteristic of the terrestrial planets? A. Primarily composed of rock and metals B. Smaller than the Jovian planets C. Closest planets to the Sun D. Many moons
many moons
Nuclear fusion in stars converts some of the __ energy of hydrogen nuclei into light and heat
mass-
Which of the following methods is useful for determining a star's approximate surface temperature? measuring the total energy given off by the star measuring its apparent brightness through two or more color filters and comparing these values measuring the radius of the star measuring the temperature of the gas cloud surrounding the star, if one exists measuring the mass of the star
measuring its apparent brightness through two or more color filters and comparing these values//As few as two brightness measurements at different wavelengths can be used to determine the effective blackbody temperature of a star.
Which of the following features of the solar system was NOT discovered by Galileo? Moons orbiting jupiter mtns and craters on the moon moons orbiting saturn phases of venus
moons orbiting saturn; Galileo didn't discover moons around Saturn (an individual named Christian Huygens did a few decades after Galileo died). However, he did discover Saturn's rings, which he described as ears.
Long period comets are thought to reside mainly in the asteroid belt. Kirkwood gaps. Interstellar Medium. Kuiper Belt. Oort Cloud.
oort cloud
If a star appears to move back and forth relative to other stars over a six-month period, this motion is due to the star's transverse motion. Doppler shift. parallax shift. radial motion. true space motion.
parallax shift
Nearly all the visible light we see from the Sun is emitted from the ___
photosphere
The light we see from the Sun comes from which layer? Photosphere Troposphere Ionosphere Chromosphere Corona
photosphere
Which of the following layers of the Sun can be seen with some type of telescope? Consider all forms of light, but do not consider neutrinos or other particles. Select all that apply. convection zone core photosphere corona radiation zone chromosphere
photosphere corona chromosphere The photosphere can be seen with visible-light telescopes, while the chromosphere is most easily observed with ultraviolet telescopes and the corona with X-ray telescopes.
Loops of glowing hydrogen seen hanging over the solar limb during totality are solar rainbows. prominences. flares. filaments. haloes.
prominences
Today we rely largely on what technique to precisely measure distances in the solar system? Today we rely largely on what technique to precisely measure distances in the solar system? Transits of Venus across the Sun Precise measurements of length of the year with atomic clocks Radar echo timings Timings of the eclipses of its moons by Jupiter's shadow Measurement of stellar parallaxes.
radar echo timings
Which of the following is not a conserved quantity? energy momentum angular momentum radiation
radiation
The ___ is the layer of the Sun between its core and convection zone
radiation zone
What two energy transport mechanisms, in order from outside the core to the surface, is found in the Sun? Radiation, convection Convection, conduction Conduction, radiation Conduction, convection Radiation, conduction
radiation, convection
The light from polaris travels through space in the form of ____ energy
radiative
When we glimpse the chromosphere at the start and end of totality, its color is white from the moonlight. red, due to ionized hydrogen at lower pressure. green (the famous flash). blue, due to the ionization of nitrogen by the magnetic fields. yellow, like the photosphere below it.
red, due to ionized hydrogen at lower pressure
the mathematical form of Kepler's third law measures the period in years and the _____ in astronomical units (AU).
semimajor axis
What is the term for loops or sheets of glowing gas ejected from active regions on the solar surface? prominences granules spicules flares
spicules// narrow jets of gas
As the solar nebular contracts due to gravitation, the cloud expands. begins to cool. changes direction of motion. spins faster. becomes more spherical in shape.
spins faster
Star A is a main sequence star of spectral type G5 and star B is a red giant of spectral type K2. Which statement below is correct? Star B is hotter than star A. Star A is hotter than star B. Star A appears brighter than star B. Star B appears brighter than star A. None of the above can be said about these two stars.
star A is hotter than star B
Star A is a main sequence star of spectral type F2 and star B is a white dwarf of spectral type B4. Which statement below is correct? Star B is hotter than star A. Star B appears brighter than star A. Star A is hotter than star B. Star A appears brighter than star B. None of the above can be said about these two stars.
star B is hotter than star A
Rank these forces from left to right based on their relative strengths between two protons separated by a few centimeters, from weakest to strongest. If you think two (or more) forces have equal strength (or essentially zero strength) in this case, show the equality by dragging one on top of the other(s). weak gravity strong electromagnetic
strong/weak gravity electromagnetic The strong and weak forces generally have effects only within atomic nuclei; on larger scales — meaning anything larger than about the size of an atom (which is thousands of times larger than a nucleus) — both the strong and weak forces have essentially zero effect, which is why they are ranked equally here. Gravity and the electromagnetic force both follow an inverse square law with distance; however, for two individual charged particles, the electromagnetic force is far stronger than gravitational force.
What important property of a star do we learn from its spectral class? mass luminosity temperature radius
temp//The temperature of a star determines at what wavelengths its atmosphere absorbs photons.
What physical property of a star does the spectral type measure? Density Temperature Composition Mass Luminosity
temperature
The absolute magnitude of a star is its brightness as seen from a distance of.... ten parsecs. one light-year. one million kilometers. one astronomical unit. 10 light-years.
ten parsecs
Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion __________. the Moon has a larger acceleration than Earth, because it has a smaller mass Earth has a larger acceleration than the Moon, because it has a larger mass the Moon and Earth both have equal accelerations, because the forces are equal
the Moon has a larger acceleration than Earth, because it has a smaller mass Newton's second law of motion, F=ma, means that for a particular force F, the product mass x acceleration must always be the same. Therefore if mass is larger, acceleration must be smaller, and vice versa.
Jupiter lies about 5 A.U. from the Sun, so at its distance: the Sun's gravity is 25 times weaker than its pull on the Earth. the Sun's gravity is just as strong as it is here at Earth. the Sun's gravity is five times weaker there than at one A.U. distance. the Sun's gravity must be five times stronger to hold massive Jupiter in orbit. the Sun's gravity is so weak that ultimately Jupiter will escape the solar system.
the Sun's gravity is 25 times weaker than its pull on the Earth.
Jupiter lies about 5AU from the sun, so at its distance.. the Sun's gravity must be five times stronger to hold massive Jupiter in orbit. the Sun's gravity is five times weaker there than at one AU distance. the Sun's gravity is so weak that ultimately Jupiter will escape the solar system. the Sun's gravity is just as strong as it is here at Earth. the Sun's gravity is 25 times weaker than its pull on the Earth.
the Sun's gravity is 25 times weaker than its pull on the Earth.
What does temperature measure? the total potential energy of particles in a substance the average kinetic energy of particles in a substance the total amount of heat in a substance the average mass of particles in a substance
the average kinetic energy of particles in a substance
Which of the following examples describes a situation where a car is experiencing a net force? the car is stopped on a hill The car is floating on a stationary boat. The car is making a gradual turn. The car is moving at constant speed.
the car is making a gradual turn
In light of modern solar system theory, why do the orbits of the planets all lie in the same plane? This happened purely by chance. The early solar nebula flattened into a disk. The angular momentum of the solar system was kept to a minimum this way. Comets would have wiped out any not in this protected plane. The Sun's gravity forced them into these orbits.
the early solar nebula flattened into a disk
If you are standing on a scale in an elevator, what exactly does the scale measure? your mass the force you exert on the scale the gravitational force exerted on you by Earth
the force you exert on the scale You probably recognize that neither your mass nor the gravitational force exerted on you change when you are in an elevator. The scale measures the force that is exerted on it, which in an elevator is a combination of the force due to your normal weight and a force due to the elevator's acceleration.
The vibrations of the Sun reveal information about the magnetic field of the Sun. the interior structure of the Sun. the temperature of the core of the Sun. the structure of the atmosphere of the Sun. the production of energy in the Sun.
the interior structure of the sun
Which of these was NOT a telescopic discovery of Galileo? the moons of Saturn the four largest moons of Jupiter the phases of Venus sunspots and the rotation of the Sun the craters and mare of the Moon
the moons of Saturn
Compared to its angular momentum when it is farthest from the Sun, Earth's angular momentum when it is nearest to the Sun is: the same less greater
the same
Given that the planet orbiting the nearby star 51 Pegasi is about 20X larger than the Earth, but 400X more massive, on that world you would weigh.... 20X more that you do here. 400X more than you do here. half as much as you do here. the same as you do here. twice as much as you do here.
the same as you do here
Given that the planet orbiting the nearby star 51 Pegasi is about 20X larger than the Earth, but 400X more massive, on that world you would weigh 400X more than you do here. the same as you do here. 20X more that you do here. twice as much as you do here. half as much as you do here.
the same as you do here.
The luminosity of the Sun is a measure of the energy emitted by the Sun at the photosphere. the energy received by the Sun on Earth's surface. the energy received by the Sun at the location of Earth. the energy received by the Sun at any location in the solar system. the total energy emitted by the Sun in all directions.
the total energy emitted by the Sun in all directions
The luminosity of the Sun is a measure of the energy emitted by the Sun at the photosphere. the energy received by the Sun on Earth's surface. the energy received by the Sun at the location of Earth. the energy received by the Sun at any location in the solar system. the total energy emitted by the Sun in all directions.
the total energy emitted by the Sun in all directions.
Suppose that two objects collide. Which of the following things is NOT the same both before and after the collision? the total temperature of the objects the total momentum of the objects the total energy of the objects the total angular momentum of the objects
the total temperature of the objects
• The star Eta Cancri is a binary system. Both stars in the binary have a surface temperature of 3000 K. However, Eta Cancri A is 106 times more luminous than Eta Cancri B. What is the primary difference between the two stars? A. The distance to the two stars B. Their size C. Their composition D. We don't have enough information to tell
their size
Star A has an absolute magnitude of -8.1 and belongs to spectral class G. Star B has an absolute magnitude of 4.3, and is also in spectral class G. Which star has the higher temperature? A. Star A B. Star B C. They have the same temperature D. Not enough information to tell
they have the same temp
In the H-R diagram, the bright blue-white stars that dominate the naked eye sky lie to the middle of the main sequence. top center. top left. bottom left. top right.
top left
T/F: Galileo's observations of the entire phase cycle of Venus proved that Ptolemy's epicycles could not be correct in keeping Venus between us and the Sun.
true
T/f: Newton's modification of Kepler's Third Law lets us measure the mass of the Sun.
true
True/False: sunspots are only about 2000K cooler than the much brighter photosphere
true
True/False: the solar corona produces a lot more X-rays than it does visible light
true
t/f: Hydrogen lines are weaker in both very hot and very cool stars.
true
t/f: A star of the Sun's diameter, but twice as hot, must be 16X more luminous than the Sun.
true
t/f: First magnitude Spica appears 2.5 times brighter than second magnitude Polaris.
true
t/f: Granulation is the most obvious proof of solar convective energy transport.
true
t/f: In the proton-proton cycle, .007 of the mass ends up as energy, not helium.
true
t/f: In the proton-proton cycle, you must first make deuterium, then helium.
true
t/f: On the main sequence, almost all stars have radii between about 0.1 and 10 times the Sun.
true
t/f: The energy of the Sun starts as radiation, but is actually transported to its surface by convection, where it is radiated off into space at last.
true
t/f: The nearest naked- eye star to our Sun, Alpha Centauri, is still over a parsec distant.
true
t/f: a type B9 star is hotter than a type A0
true
t/f: large sunspots are larger than our whole planet
true
t/f: the sun is a fairly normal star
true
t/f: transits of venus were critical in early determinations of the AU
true
The geocentric model, in all of its complexity, survived scientific scrutiny for almost 1,400 years. However, in modern astronomy, scientists seek to explain the natural and physical world we live in as simply as possible. The complexity of Ptolemy's model was an indicator that his theory was inherently flawed. Why, then, was the geocentric model the leading theory for such a long time, even though the heliocentric model more simply explained the observed motions and brightness of the planets? Check all that apply. From Earth, all heavenly bodies appeared to circle around a stationary Earth. The geocentric model conformed to both the philosophical and religious doctrines of the time. The heliocentric model did not make noticeably better predictions than the geocentric model. Ancient astronomers did not observe stellar parallax, which would have provided evidence in favor of the heliocentric model. The complexity of the geocentric model was appealing to most ancient astronomers.
From Earth, all heavenly bodies appeared to circle around a stationary Earth. The geocentric model conformed to both the philosophical and religious doctrines of the time. The heliocentric model did not make noticeably better predictions than the geocentric model. Ancient astronomers did not observe stellar parallax, which would have provided evidence in favor of the heliocentric model. The geocentric model was the leading model for hundreds of years because it conformed to the common beliefs from observations and religious doctrine of the time. However, the heliocentric model gained widespread acceptance when astronomers obtained new evidence after the time of Copernicus. These astronomers popularized his view and helped pave the way for our current understanding of the solar system.
How do scientists use their imagination and creativity when analyzing and interpreting data? Again, keep your answer to 2-3 sentences.
Galileo Galilei viewed the surface of the Moon, which revealed mountains, valleys, and craters. He used his imagination and creativity, while viewing through the telescope, that the sun showed dark spots that appeared, disappeared, and changed shaped. He was able to draw the same conclusion for that of the Moon; the craters, mountains, and valleys he drew darker, similarly to the way in which the sun spots appeared, disappeared, and changed shape.
Hydrostatic equilibrium in our Sun is the balance between convection and radiation. pressure and radiation. gravitation and pressure. radiation and gravitation. convection and gravitation.
Gravitation and pressure
What energy transformation takes place when a cloud of gas contracts? A. Thermal energy to chemical energy B. Kinetic energy to gravitational potential energy C. Rest-mass energy to kinetic energy D. Gravitational potential energy to thermal energy
Gravitational potential energy to thermal energy
As a large cloud collapses, what energy transformation is taking place? A. Chemical to thermal B. Gravitational potential to thermal C. Kinetic to thermal D. Angular momentum to thermal
Gravitational potential to thermal// angular momentum is NOT a form of energy!
What is the process of accretion? the separation of materials in a protoplanet by density, with dense material in core the process by which the solar nebula became heated during its collapse growth of an object by the accumulation of matter the breakup of large objects by violent collisions with other similar-sized objects the period of time during which the Sun swept away all the excess material in the solar nebula
Growth of an object by the accumulation of matter
What contribution to astronomy was made by Tycho Brahe? Retrograde motion must be explained by epicycles larger than those of Ptolemy. His telescope revealed the moons of Jupiter before Galileo noted them. The planets' orbits around the Sun are ellipses, not circles. His observations of planetary motion with great accuracy proved circular orbits could not work. The Earth is not the center of the Universe.
His observations of planetary motion with great accuracy proved circular orbits could not work.
describe the process and nature of science in your own words.
I've understood the nature of science as the outcome of fiercely and consistently following the scientific method - the process that must be followed in order to produce results that make sense holistically. These processes are researched, conducted, and analyzed on a daily basis, which produce results that may draw new or contradictory conclusions. The nature of science is constantly changing, yet basic facts remain the same until proven wrong.
Which of the following must occur for a star's core to reach equilibrium after an initial change in fusion rate? Check all that apply. If the fusion rate initially decreases, then the core expands. If the fusion rate initially increases, then the core expands. If the fusion rate initially decreases, then the core contracts. If the fusion rate initially increases, then the core contracts.
If the fusion rate initially increases, then the core expands. If the fusion rate initially decreases, then the core contracts. Increasing the fusion rate releases more energy into the core, which raises the temperature and increases the internal pressure, causing the core to expand. Decreasing the fusion rate means less energy is released, so the temperature and internal pressure would decrease. As you can see in the video, the solar thermostat keeps the fusion rate fairly steady in a star like the Sun because a temperature increase causes the core to expand while a temperature decrease causes the core to contract.
Star A has an absolute magnitude of 2.5 and star B has an apparent magnitude of 2.5, but star A is a main sequence star and star B is a red giant. Which statement below is correct? Star A appears brighter than star B, but star B and star A have the same intrinsic brightness. Star B appears brighter than star A, but star B and star A have the same intrinsic brightness. Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A. Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B. It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
The density of the Sun is most similar to which object? The Earth Jupiter The Moon Mercury Halley's Comet's nucleus
Jupiter
Find Jupiter's mass from the fact that its moon Io orbits every 42.5 hours at an average distance of 422,000 kilometers. Express your answer to three significant figures and include the appropriate units. MJupiter =
MJupiter = 1.90×1027 kg
During the Dark Ages (roughly from the 5th to the 10th century A.D.), turmoil in Europe largely halted the progress of Western science. Which culture provided the vital link between the astronomy of ancient Greece and that of medieval Europe during this time? North American Chinese Muslim South American
Muslim For six centuries, Islamic astronomy flourished and grew, preserving and augmenting the knowledge of the Greeks. Its influence on modern astronomy is subtle, but quite pervasive.
Which of the following is the correct list of regions of the Sun in increasing order of temperature? A. Photosphere, convection zone, radiation zone, core B. Core, radiation zone, convection zone, photosphere C. Core, convection zone, photosphere, radiation zone D. Radiation zone, photosphere, convection zone, core
Photosphere, convection zone, radiation zone, core
From inside out, which is in the correct order for the structure of the Sun? Convective zone, radiative zone, granulation Core, convective zone, radiative zone Core, chromosphere, photosphere Photosphere, radiative zone, corona Radiative zone, convective zone, chromosphere
Radiative zone, convective zone, chromosphere
Star A and star B both have an apparent magnitude of 4.0, but star A has an absolute magnitude of 1.0 and star B has an absolute magnitude of 7.0. Which statement below is correct? Star A appears brighter than star B, but star B and star A have the same intrinsic brightness. Star B appears brighter than star A, but star B and star A have the same intrinsic brightness. Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A. Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B. It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B.
Star A and star B both have an apparent magnitude of 7.0, but star A is at a distance of 15 pc and star B is at a distance of 30 pc. Which statement below is correct? Star A appears brighter than star B, but star B and star A have the same intrinsic brightness. Star B appears brighter than star A, but star B and star A have the same intrinsic brightness. Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A. Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B. It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A.
Star A and star B both have an absolute magnitude of 2.0, but star A has an apparent magnitude of 5.0 and star B has an apparent magnitude of 7.0. Which statement below is correct? Star A appears brighter than star B, but star B and star A have the same intrinsic brightness. Star B appears brighter than star A, but star B and star A have the same intrinsic brightness. Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A. Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B. It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
Star A appears brighter than star B, but star B and star A have the same intrinsic brightness.
Star A and star B both have an absolute magnitude of 2.0, but star A is at a distance of 50 pc and star B is at a distance of 20 pc. Which statement below is correct? Star A appears brighter than star B, but star B and star A have the same intrinsic brightness. Star B appears brighter than star A, but star B and star A have the same intrinsic brightness. Star A and star B appear to have the same brightness, but star B is intrinsically brighter than star A. Star A and star B appear to have the same brightness, but star A is intrinsically brighter than star B. It is impossible to determine how bright these stars are or appear to be relative to one another, given the information above.
Star B appears brighter than star A, but star B and star A have the same intrinsic brightness.
Two red stars have surface temperatures of 3000 K, but Star A's luminosity is about 5% of the Sun's and Star B's luminosity is about 32,000 times the luminosity of the Sun. How much bigger is star B than star A? They are the same size. Star B's radius is about 800 times larger than star A's radius. Star B's radius is about 640,000 times larger than star A's radius. Star B's radius is about 16 times larger than star A's radius. This cannot be determined from the information given.
Star B's radius is about 800 times larger than star A's radius.
If the rate of fusion were to suddenly decrease in the core of the Sun, what would happen? A. The Sun would stay exactly the same because it is static B. The Sun would start to shrink in size C. The Sun would start to expand in size D. We don't have enough information to answer this question
The Sun would start to shrink in size// Gravity would start to win the battle and pull the outer layers of the Sun towards the center
What would happen if the fusion rate in the core of the Sun were increased but the core could not expand? The Sun's core would start to cool down, and the rate of fusion would decrease. The Sun's core would reach a new equilibrium at a lower temperature. The Sun's core would reach a new equilibrium at a higher temperature. The Sun's core would start to heat up, and the rate of fusion would increase even more.
The Sun's core would start to heat up, and the rate of fusion would increase even more. As you know from Part B, an increase in the fusion rate will cause the core to expand in a normal (or main-sequence) star like the Sun, and this expansion will restore core equilibrium. However, if for some reason the core could not expand, the higher temperature would make the fusion rate increase even more, creating a positive feedback loop in which the fusion rate and temperature would keep increasing. There would be no equilibrium. In fact, as you'll learn when you study stellar life cycles, this is essentially what will occur when the Sun nears the end of its life.
What is it about the Sun's corona that astronomers don't understand? The corona seems to absorb 2/3 of the neutrinos that pass through it. The corona is much hotter than layers of the Sun that are closer to the solar interior. The Sun's corona extends to the outer reaches of the solar system. No one knows why that part of the Sun's atmosphere does not drift away into space. During total solar eclipses, the corona sometimes disappears from view.
The corona is much hotter than layers of the Sun that are closer to the solar interior.
As you found in Part A, your weight will be greater than normal when the elevator is moving upward with increasing speed. For what other motion would your weight also be greater than your normal weight? The elevator moves upward with constant velocity. The elevator moves downward with constant velocity. The elevator moves upward while slowing in speed. The elevator moves downward while slowing in speed. The elevator moves downward while increasing in speed.
The elevator moves downward while slowing in speed. When the elevator is moving downward, a downward acceleration would mean an increasing downward speed. Therefore, as your answer correctly states, an upward acceleration would mean a decreasing downward speed.
When a rock is held above the ground, we say it has some potential energy. When we let it go, it falls and we say the potential energy is converted to kinetic energy. Finally, the rock hits the ground. What has happened to the energy? The energy goes into the ground and, as a result, the orbit of the earth about the Sun is slightly changed. It is transformed back into gravitational potential energy. The energy goes to producing sound and to heating the ground, rock, and surrounding air. It is lost forever. Energy does not have to be conserved. The rock keeps the energy inside it (saving it for later use).
The energy goes to producing sound and to heating the ground, rock, and surrounding air.
Which of the following is NOT a way in which the terrestrial and jovian planets differ? Which of the following is NOT a way in which the terrestrial and jovian planets differ? The terrestrial planets that do have atmospheres have ones made of heavier compounds in general than the atmospheres of the jovian planets. The terrestrial worlds have few or no moons, whereas the jovian worlds have many moons. The terrestrial worlds are small and dense, whereas the jovian worlds are large and gaseous. The orbits of the terrestrial worlds are relatively close together, whereas the orbits of the jovian worlds are far apart. The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets.
The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets.
A high-mass star has more "fuel" than a low-mass star. Which lives longer? Why? The lifetime of a star is independent of mass. The high-mass star lives longer because it has more "fuel to burn" and therefore takes longer to consume it all. The low-mass star lives longer because, even though it has less "fuel," it consumes fuel at a much slower rate than the high-mass star. The lifetime of a star depends on more than just mass, so not enough information is given.
The low-mass star lives longer because, even though it has less "fuel," it consumes fuel at a much slower rate than the high-mass star.
Why does the surface of the Sun appear to have a sharp edge? The photosphere is much less dense than the convection zone. The photosphere is transparent to radiation. The photosphere is cooler than the regions below it. The photosphere is relatively thin compared to the other atmospheric regions.
The photosphere is relatively thin compared to the other atmospheric regions. The thinness of the photosphere makes the Sun appear to have a distinct edge.
If the ratio of Potassium to Argon found in meteorites were higher than we actually measure (i.e. more Potassium, less Argon), what would this tell us about the age of the solar system? A. The solar system is younger than 4.6 billion years old B. The solar system is 4.6 billion years old C. The solar system is younger than 4.6 billion years old D. Not enough information to tell
The solar system is younger than 4.6 billion years old
You take a spectrum of a sunspot, and notice three narrowly spaced absorption lines where you expect only one. What can you conclude from this observation? A. The strong magnetic fields are located at the position of the sunspot - the Zeeman Effect B. That two additional elements are found at the position of the sunspot C. That some material in the sunspot is moving away from us D. That some material in the sunspot is moving towards us
The strong magnetic fields are located at the position of the sunspot - the Zeeman Effect
What factor caused different planets to form out of different types of material? The variation in temperature throughout the solar nebula; the higher the temperature, the lower the percentage of light elements in the forming planet. The angular momentum of the forming planet; faster rotating planets lost the lightest elements. The quantity of dust particles in the solar nebula; more dust caused some planets to contain heavier elements. The angular momentum of the solar nebula pushed the heavy elements towards the outer regions of the nebula. The innate variation of chemical composition of the original nebula; the outer parts of the nebula contained a greater abundance of heavy elements.
The variation in temperature throughout the solar nebula; the higher the temperature, the lower the percentage of light elements in the forming planet.
Upon what data do measurements of sizes of eclipsing binaries depend? Their orbital periods and separations Their Doppler shifts and durations of stages of their eclipses Their temperatures and speeds Their temperatures and masses Their masses and luminosities
Their Doppler shifts and durations of stages of their eclipses
While observing the Sun, you note a large number of sunspots. What can you conclude? The Sun is less luminous than usual. The Sun's rotation is slower than average. This is a period of low solar activity. There are likely to be an above average number of flares and prominences. Earth's climate will be unusually cold.
There are likely to be an above average number of flares and prominences.
Why do sunspots appear dark? A. They are much hotter than the rest of the photosphere and so emit very little visible light B. They are regions where no light is produced, and so appear dark C. They are cooler than the rest of the photosphere, and so appear darker D. They are the same temperature as the rest of the photosphere, but the light is scattered away by magnetic fields`
They are cooler than the rest of the photosphere, and so appear darker
Which of the following statements about solar sunspots is NOT true? They cluster at high latitudes when solar activity is at a minimum. They reach maximum numbers at roughly 11-year intervals. They appear in larger numbers at about the time of the solar maximum. They are distributed approximately uniformly over the Sun's surface both in position and in time. They typically measure about 10,000 km across (approximately the size of Earth!).
They are distributed approximately uniformly over the Sun's surface both in position and in time. Both portions of this statement are incorrect. New sunspots appear closer to the equator and older ones are at higher latitudes, and the number of sunspots ranges from essentially zero to 100-200 at maximum solar activity, with an approximate 11-year cycle.
Sunspots are dark splotches on the Sun. Which statement is TRUE? They are solid bodies floating on the surface of the Sun. They are associated with areas of very low magnetic fields. They are hotter than the surrounding areas of the Sun. They are extremely hot, but cooler than the surrounding areas of the Sun. They are extremely cold objects, as cold as Pluto.
They are extremely hot, but cooler than the surrounding areas of the Sun.
How would sunspots appear if you could magically remove them from the Sun? They would shine bright orange in color, like Arcturus. They would shine only with reflected sunlight, appearing similar to Venus. They would not appear any differently than on the surface of the Sun. They would appear blue-white, like Sirius but brighter. Because sunspots are dark spots, they would be invisible against the blackness of space.
They would shine bright orange in color, like Arcturus.
True/False: At very large distances from the Sun, its corona turns into the solar wind.
True
Our Sun is classified as a G2 star. Vega, which is 26.4 light-years away, is an A0 star, and Barnard's Star is type M5. How do these stars compare in terms of temperature? The Sun is cooler than Vega, which in turn is cooler than Barnard's Star. The Sun is hotter than Vega, which in turn is hotter than Barnard's Star. To answer this question, we need to know the distance to Barnard's Star as well. Vega is cooler than the Sun, which in turn is cooler than Barnard's Star. Vega is hotter than the Sun, which in turn is hotter than Barnard's Star.
Vega is hotter than the Sun, which in turn is hotter than Barnard's Star.
Rank these forces from left to right based on their relative strengths between two protons located within the nucleus of an atom, from weakest to strongest. strong weak gravity electromagnetic
Weakest to Strongest: gravity, weak, electromagnetic, strong On a per particle basis, gravity is by far the weakest of the four forces. Next weakest is the weak force, which operates only over very short distances (which is why it can be felt within an atomic nucleus, but not on much larger scales). The electromagnetic force tends to repel two protons (because they both have the same charge), so the fact that the protons remain together in the nucleus tells us that the strong force (which holds the nucleus together) must be stronger than the electromagnetic force.
When is an object accelerating? A.Only when its speed is changing B. Only when its direction is changing C. When either its speed or direction is changing D. Only when it starts moving from rest
When either its speed or direction is changing
The nucleus, or main solid body, of a comet has a typical size of a few centimeters. a few kilometers. a few meters. a few thousand kilometers. a few hundred kilometers.
a few kilometers
Rank these forces from left to right based on their relative strengths acting between Earth and the Sun, from weakest to strongest. If you think two (or more) forces have equal strength (or essentially zero strength) in this case, show the equality by dragging one on top of the other(s). electromagnetic strong weak gravity
weak/strong electromagnetic gravity The strong and weak forces generally have effects only within atomic nuclei; on larger scales — meaning anything larger than about the size of an atom (which is thousands of times larger than a nucleus) — both the strong and weak forces have essentially zero effect, which is why they are ranked equally here. Gravity and the electromagnetic force both follow an inverse square law with distance, which is why Part B showed that the electromagnetic force is stronger between two individual charged particles. But for very large masses, such as Earth and the Sun, the electromagnetic force becomes very weak because the objects are essentially neutral. In contrast, gravity grows stronger for larger masses, which is why gravity dominates large-scale interactions in the universe.
Stars that have masses similar to the Sun's, and sizes similar to the Earth are main sequence stars. red dwarfs. red giants. brown dwarfs. white dwarfs.
white dwarfs
The average temperature of the Sun's surface is 5800 K, and its spectrum peaks at a wavelength of 500nm. What would the peak wavelength be for sunspots, with an average temperature of 4000 K? A. 1000 nm B. 725 nm C. 400 nm D. 250 nm
wien's law !!! 725nm - infrared light
