Astronomy final exam review: learning questions and quiz questions
What seems to have made the very long cliffs seen on Mercury? a) Volcanoes b) Earthquakes c) Cooling and shrinking when the planet became geologically dead d) Meteorite impacts e) None of the above
Cooling and shrinking when the planet became geologically dead
Let's say that we send this "starshot" at 1/5th the speed of light to take a picture of Proxima b. If we send it today, how long do we need to wait for that picture? A. less than one year B. 5 years C. 20 years D. 24 years
24 years
What do astronomers think Pluto is? a) A planet like Earth b) A Kuiper belt comet c) An escaped moon of Neptune d) An asteroid
A Kuiper belt comet
Which is hottest? A. A blue star B. A red star C. A planet that emits only infrared light
A blue star
Imagine you're the head of a funding agency that can afford to build only one telescope. Which of the four proposed telescopes below would be best to support? a) A gamma ray telescope in Antarctica b) A radio telescope in orbit above the Earth c) A visible telescope located high on a mountain in Peru d) An ultraviolet telescope located in the Mojave desert
A visible telescope located high on a mountain in Peru
If we can't see the Sun's interior, how do we know what it is like? a) Sunquakes b) Neutrinos c) Our understanding of gravitational equilibrium d) B and C e) A, B, and C
A, B, and C
Jupiter is about three times as massive as Saturn, but only slightly larger. Why? a) It is made of stronger material b) It is made of weaker material c) Adding mass increases gravity and compresses gases d) Because they are made of different gases e) None of the above
Adding mass increases gravity and compresses gases
Titan is the only moon with a thick atmosphere, and its surface: a) Has never been seen b) Has been seen by infrared light and spacecraft c) Is warmed by a greenhouse effect d) Has oceans of methane and ethane e) All except A
All except A
Why do Jupiter, Saturn, Uranus, and Neptune all have rings? a) Rings were left over from solar system formation b) They all captured particles c) All four planets had a large moon that disintegrated d) All have small moons and small orbiting particles that constantly collide and make rings
All have small moons and small orbiting particles that constantly collide and make rings
How does the cooling of planets and potatoes vary with size? a) Larger makes it harder for heat from inside to escape b) Larger has a bigger ratio of volume (which needs to cool) to surface area (the surface is where cooling happens) c) Larger takes longer to cool d) All of the above
All of the above
Which of the following would increase the tidal heating of a moon? a) A more elliptical orbit b) Larger size c) Orbit around a larger planet d) All of the above e) A and C
All of the above
How does solar activity affect Earth? a) It can make beautiful aurorae. b) It can cause geomagnetic storms. c) It can occasionally harm satellites. d) It can sometimes disrupt electrical power. e) All of the above.
All of the above.
What advantages come from putting a telescope in space? a) All wavelengths can be seen, even those that don't penetrate the atmosphere b) The image may be sharper, without moving air to blur it c) You are closer to the stars, for a better view d) All of the above e) A and B
All wavelengths can be seen, even those that don't penetrate the atmosphere and The image may be sharper, without moving air to blur it
About how long does it take light to go from Earth to Jupiter? a) An hour b) A week c) A month d) A year
An hour
Why are different stars seen in differen seasons? a) The tilt of Earth's axis b) Stars move during the year c) As Earth orbits the Sun, we see the Sun in front of different constellations d) Precession
As Earth orbits the Sun, we see the Sun in front of different constellations
Which of the following is true? A).Astronauts in space can be weightless. b) Astronauts in space can be massless. c) Astronauts are far enough from Earth they don't feel their weight. d) Without air there can be no weight. e) All of the above (show entire page)
Astronauts in space can be weightless
Why does the Sun shine? a) Because it is burning. b) Because of its chemical energy. c) Because of its gravitational energy. d) Because of nuclear fusion. e) Because of nuclear fission.
Because of nuclear fusion
Why do stars of spectral types O and B show few absorption lines a) Many elements have been used up in these stars. b) These stars are old and were formed before there were many elements in the galaxy. c) Many atoms in these stars are ionized-have lost electrons-so can't absorb. d) Much of their absorption is in the ultraviolet. e) C and D
C and D
If there was no greenhouse effect, Earth: a) Would be safer than it is today b) There would be no human presence, since humans make the greenhouse effect c) Earth's average temperature would be colder than freezing d) We would be in danger from ultraviolet radiation
Earth's average temperature would be colder than freezing
I measure a line in the lab at 500.7 nm. The same line in a star has wavelength 502.8 nm. What can I say about this star? A. It is moving away from me. B. It is moving toward me. C. It has unusually long spectral lines
It is moving away from me.
Objects are located on the celestial sphere in units of: a) Miles b) Kilometers c) Light years d) Parsecs e) Degrees
Degrees
If a small weather satellite and the large International Space Station are orbiting Earth at the same altitude above Earth's surface, which of the following is true? A. The large space station has a longer orbital period. B. The small weather satellite has a longer orbital period. C. Each has the same orbital period
Each has the same orbital period
If Earth's orbit were a perfect circle, we would not have seasons? a) True, because Earth would be at the same distance from the Sun throughout its orbit, there would be no summer or winter. b) True, it is the deviations from a circular orbit that create the seasons. c) False, the seasons are due to the tilt of Earth's axis, not its distance from the Sun. d) False, the poles would still be cooler than the equator and seasonal variations would therefore still exist.
False, the seasons are due to the tilt of Earth's axis, not its distance from the Sun.
Which is the correct reasoning for why a gamma ray telescope located in Antarctica that is to be used to look for evidence of black holes in the centers of galaxies would not get funded? a) There is no way to detect the presence of a black hole. b) Gamma rays are too energetic to detect with a telescope. c) You can't build a functioning telescope in Antarctica. d) Gamma rays don't penetrate Earth's atmosphere
Gamma rays don't penetrate Earth's atmosphere.
What is the structure of Jupiter like? a) Rocky core, thin atmosphere b) Rocky core, thick atmosphere c) Gaseous on the outside, then liquid hydrogen, more dense metallic hydrogen, rocky/icy/ metallic core d) Gaseous on the outside, then liquid hydrogen, then helium, then the other elements
Gaseous on the outside, then liquid hydrogen, more dense metallic hydrogen, rocky/icy/ metallic core
If you could see stars during the day, this is what the sky would look like at noon on a given day. The Sun is near the stars of the constellation Gemini. Near which constellation would you expect the Sun to be located at sunset? a) Leo b) Cancer c) Gemini d) Taurus e) Pisces
Gemini
In our 1:6 trillion scale model of the solar system, about how large is the Sun? A. Basketball B. Grapefruit C. Grain of Sand D. Size of an atom
Grain of Sand
When an astronomer describes the altitude of something in the local sky, he or she means a) How high above the horizon something is in the sky, in units of miles or kilometers b) How high above the horizon something is in the sky, in units of degrees c) The direction toward something-such as north, south, east, or west
How high above the horizon something is in the sky, in units of degrees
Surprising discovery?: Saturn's core is pockmarked with impact craters and dotted with volcanoes erupting basaltic lava. a) Plausible. Saturn's moons also show impact craters and volcanoes. b) Plausible. Saturn's atmosphere originated from the volatiles in impactors that were released via volcanic activity. c) Implausible. No impactors would survive the immense pressures at the depth of Saturn's core. d) Implausible. Any large impactor approaching Saturn would be broken up by tidal forces. e) Implausible. Saturn's high rotation would prevent an impactor from reaching its core.
Implausible. No impactors would survive the immense pressures at the depth of Saturn's core.
Surprising discovery?: A planet in another solar system has an Earth-like atmosphere with plentiful oxygen, but no life of any kind. a) Plausible. Life requires far more than oxygen to exist. b) Plausible. The oxygen may have been transported there by cometary impacts. c) Implausible. Oxygen is highly reactive and its presence in an atmosphere suggests replenishment by a living organism of some sort. d) Implausible. Oxygen is essential to life
Implausible. Oxygen is highly reactive and its presence in an atmosphere suggests replenishment by a living organism of some sort
Surprising discovery?: A mission to Pluto finds that it has lakes of liquid water on its surface. a) Plausible. Other icy bodies at great distances from the Sun may also have liquid water. b) Plausible. Studies of Pluto's surface show a long, narrow feature that has been suggested to be a lake. c) Implausible. Water would be frozen at Pluto's temperature, and we know of no extra heat sources. d) Implausible. Pluto is mostly made of rock and metals, not water.
Implausible. Water would be frozen at Pluto's temperature, and we know of no extra heat sources.
Which of the following has to be true for an object that has no net force? A. It will have no acceleration B. Its acceleration and velocity are the exact same just in opposite directions C. Its acceleration and velocity are the exact same and in the same direction D. None of the above
It will have no acceleration
Jupiter does not have a large metal core like Earth. How can it have a magnetic field? a) The magnetic field is left over from when Jupiter accreted b) Its magnetic field comes from the Sun c) It has metallic hydrogen inside, which circulates and makes a magnetic field d) That's why its magnetic field is weak
It has metallic hydrogen inside, which circulates and makes a magnetic field
If a star was moved twice as far away, what would happen to it's appearance? a) It would get twice as faint b) It would get four times fainter c) It would get fainter and redder d) It would get fainter and bluer e) If moved only two times farther, you wouldn't notice much change
It would get four times fainter
If Earth was more reflective (had a higher albedo) what would happen to its temperature? a) It would go up b) It would go down c) It wouldn't change
It would go down
If Earth didn't have an atmosphere, what would happen to its temperature? a) It would go up a little b) It would go up a lot c) It would go down a little d) It would go down a lot e) It wouldn't change
It would go down a lot
Saturn's average density is less than water's. Suppose Saturn were placed on a much larger planet made entirely of water. What would happen? a) It would float. b) It would sink to the center of the water planet. c) It would be spread out due to the rotation of the water planet. d) It would merge into the water planet; denser materials sinking toward the core and lighter materials forming part of the atmosphere. e) There would be a devastating impact and Saturn would be torn apart to form a giant ring system around the water planet.
It would merge into the water planet; denser materials sinking toward the core and lighter materials forming part of the atmosphere
To measure a star's true brightness, or luminosity, you need to know a) Its temperature and distance b) Its temperature and color c) Its apparent brightness and distance d) Its apparent brightness and color e) Its distance, apparent brightness, and color or temperature
Its apparent brightness and distance
Jupiter and one of its moons feel a gravitational force toward each other. How does the force felt by each of the two objects relate? A. Jupiter feels a lesser force because it is more massive and pulling the moon toward it B. Jupiter's moon feels a lesser force because it is much less massive C. Jupiter and its moon feel the same force but in opposite directions D. None of the above
Jupiter and its moon feel the same force but in opposite directions
How does Io get heated by Jupiter? a) Light from the Sun b) Infrared radiation c) Jupiter causes tidal heating by pulling harder on one side than the other d) Volcanoes
Jupiter causes tidal heating by pulling harder on one side than the other
What is the most geologically active world we know of in the solar system? a) Earth-due to its earthquakes and volcanoes b) Mercury, the hottest planet c) Mars d) Jupiter e) Jupiter's moon Io
Jupiter's moon Io
The largest optical telescopes are designed to have a) High magnification, large collecting area, and high angular resolution. b) High magnification, large collecting area, and low angular resolution. c) Low magnification, large collecting area, and low angular resolution. d) Large collecting area and high angular resolution - the magnification is of secondary importance. e) Large collecting area and low angular resolution - the magnification is of secondary importance
Large collecting area and high angular resolution - the magnification is of secondary importance.
Why can't we see a galaxy that is 20 billion light-years away? (Assume the universe is 14 billion years old.) A. No galaxies exist at such a great distance. B. Galaxies may exist at that distance, but their light would be too faint for our telescopes to see. C. Looking 15 billion light-years away means looking to a time before the universe existed
Looking 15 billion light-years away means looking to a time before the universe existed.
What is the source of Earth's magnetic field? a) Magnetic rocks b) Magnetized iron in Earth's crust c) Magnetized iron in Earth's core d) Molten metal circulating inside of Earth, moving electrons like in a wire
Molten metal circulating inside of Earth, moving electrons like in a wire
When is the Sun directly overhead at noon in North America? a) March 21 b) June 21 c) July 21 d) Never
Never
When might you see the planet Jupiter in the Big Dipper? a) Summer b) Winter c) Only after midnight d) Never
Never
Last night I saw Mars move westward through the sky in its apparent retrograde motion. a) Yes, this occurs during certain times of the year when Earth overtakes Mars in its orbit. b) Yes, this is a well studied phenomenon and its explanation proved a challenge to ancient astronomers. c) All planets (and stars) move westward because of Earth's rotation, so this is not unusual. d) No, apparent retrograde motion is only noticeable over many nights, not a single night. e) No, because Mars lies further from the Sun than Earth, it does not undergo retrograde motion
No, apparent retrograde motion is only noticeable over many nights, not a single night
If fusion in the solar core ceased today, worldwide panic would break out tomorrow as the Sun would begin to grow dimmer. a) Yes, because Earth would quickly freeze over. b) Yes, because Earth would no longer be bound to the solar system and would drift into space. c) Yes, because the Sun would collapse and the planets would soon follow. d) No, it takes thousands of years for photons created in nuclear reactions at the solar core to reach the surface. e) No, the Sun would continue to glow brightly for billions of years because of gravitational contraction.
No, it takes thousands of years for photons created in nuclear reactions at the solar core to reach the surface.
Can unique experiments can be carried out in the Space Station because of the lack of gravity? a) Yes, and the Space Station was built in order to escape gravity. b) This is not quite right - the Space Station still feels the effect of Earth's gravity but it is greatly diminished and the experiments are therefore referred to as being performed in "micro-gravity." c) No, the uniqueness of the experiments is not due to the lack of gravity but to weightlessness. d) No, similar experiments can be performed on the highest mountaintops on Earth.
No, the uniqueness of the experiments is not due to the lack of gravity but to weightlessness.
Suppose a comet had a very eccentric orbit that brought it quite close to the Sun at closest approach (perihelion) and beyond Mars when furthest from the Sun (aphelion), but with an average distance of 1 AU. How long would it take to complete an orbit and where would it spend most of its time? a) One year, mostly beyond Earth's orbit. b) Over one year, mostly beyond Earth's orbit. c) Less than one year, mostly within Earth's orbit d) It depends on the exact value of the eccentricity
One year, mostly beyond Earth's orbit.
If you travel for one year at the speed of light, where would you end up? A. At Jupiter B. In the outer solar system C. Outside the solar system D. Past the nearest stars
Outside the solar system
Why don't we glow in the dark? A. People do not emit any kind of light. B. People only emit light that is invisible to our eyes. C. People are too small to emit enough light for us to see. D. People do not contain enough radioactive material.
People only emit light that is invisible to our eyes.
Surprising discovery?: A jovian planet in another star system is found to have a moon as big as Mars. a) Plausible. There is no reason why jovian planets cannot have such large moons. b) Plausible. Jupiter itself has several moons as large as Mars. c) Plausible. Astronomers have already found large planets and moons around other star systems. d) Implausible. Any moon that was as large as Mars would be torn apart by tidal forces. e) Implausible. Any moon that was as large as Mars would be called a planet it its own right.
Plausible. There is no reason why jovian planets cannot have such large moons. b
In summer in the northern hemisphere, what is the Sun's daily motion? a) Rises in the east, sets in the west b) Rises north of east, sets south of west c) Rises north of east, sets north of west
Rises north of east, sets north of west
In the cosmic calendar, where the entire history of the universe is compressed into one "year" spanning Jan 1 through Dec 31, about when did the Earth form? A. Jan 1 B. May 1 C. Sep 1 D. Dec 1
Sep 1
About how long does it take a spacecraft to go from Earth to Jupiter? a) A week b) A month c) A year d) Several years e) Several decades
Several years
If you were on the Moon, Earth would a) Show no phases b) Show phases the same as the moon (when it is full Moon it is full Earth, etc.) c) Show phases opposite to the Moon (when it is full Moon it is new Earth, etc.)
Show phases opposite to the Moon (when it is full Moon it is new Earth, etc.)
Which of the following statements is true? A. High tide only occurs with a full moon. B. A spring tide only occurs with a new moon. C. The Sun's tidal forces are equally as strong as the Moon's tidal forces. D. Tidal forces on the Moon from the Earth are causing the Moon to speed up and move further away as it orbits the Earth
Spring tide only occurs with a new moon
The new moon sets at approximately a) Midnight b) Sunset c) Sunrise d) 9 or 10 p.m. e) It rises at different times during the year
Sunset
The Sun's visible surface, or photosphere, has regions of strong magnetic field called a) Granulation b) Magnetic traps c) Magnetic bottles d) Sunspots e) Sun loops
Sunspots
What is the reservoir of cold comets beyond Pluto called? a) The comet reservoir b) The extrasolar comet bank c) The Kuiper belt d) Interstellar space e) Planet X
The Kuiper belt
Consider two asteroids in the inner solar system, one which orbits at an average distance of 3 AU and one which orbits at an average distance of 4 AU. Also consider two comets in the outer solar system, one which orbits at an average distance of 31 AU and one that orbits at an average distance of 32 AU. Which pair will have the larger difference in orbital speeds? a) The comets. b) The asteroids. c) The difference in orbital speeds will be the same for each pair. d) We need to know the eccentricities of each object.
The asteroids
Imagine that you throw a ball directly upward. Which of the following statements best describes how Newton's Second Law accounts for the motion of the ball when it reaches its maximum height? A. The ball has a velocity that is zero and an acceleration that is zero. B. The ball has a velocity that is upward and an acceleration that is downward. C. The ball has a net force that is downward and an acceleration that is downward. D. The ball has a net force that is downward and a velocity that is downward. E. The ball has a net force that is downward and an acceleration of zero.
The ball has a net force that is downward and an acceleration that is downward
Why is the sky blue? a) The reflection of the ocean b) Blue is the color of oxygen gas c) Blue is the color of nitrogen gas d) The blue light in white sunlight scatters more than red light e) Clouds
The blue light in white sunlight scatters more than red light
A map of the entire sky is called a) A meridian b) A sky finder c) The celestial sphere d) The galactic directory
The celestial sphere
What would happen inside the Sun if a slight rise in core temperature led to a rapid rise in fusion energy? A. The core would expand and heat up slightly. B. The core would expand and cool. C. The Sun would blow up like a hydrogen bomb
The core would expand and cool.
If the fusion in the Sun's core sped up slightly, releasing more energy, what would happen? a) Not much, since the core is deep inside the Sun. b) The core would expand. c) The color of the Sun would change. d) None of the above.
The core would expand.
Which of the following parts of an ellipse is a measure of its shape? a) The semi-major axis b) The focus c) The eccentricity
The eccentricity
What is the main reason that Venus is warmer than Earth a) Venus is closer to the Sun than Earth. b) Venus has a higher reflectivity than Earth. c) Venus has a lower reflectivity than Earth. d) The greenhouse effect is much stronger on Venus than on Earth. e) Human presence on Earth has led to declining temperatures.
The greenhouse effect is much stronger on Venus than on Earth
Suppose that, somehow, all plants died out. What would happen to the oxygen in our atmosphere? a) The oxygen would eventually be used up in oxidation reactions with the surface. b) The oxygen would initially decrease, but as greenhouse gases and temperature increased, it would recover to its normal value. c) The oxygen would increase as plants would not exist to remove it from the atmosphere. d) Plants grow by intaking carbon and therefore the oxygen content would be unaffected.
The oxygen would eventually be used up in oxidation reactions with the surface.
Why are the Moon and planets seen only in the constellations of the zodiac? a) The planets all revolve in the same direction around the Sun b) The planets all orbit in nearly the same plane, and the zodiacal constellations are in that plane. c) The constellations in the zodiac are the oldest, and the planets have been known from ancient times d) None of the above reasons
The planets all orbit in nearly the same plane, and the zodiacal constellations are in that plane
Why is a rose red? A. The rose absorbs red light. B. The rose transmits red light. C. The rose emits red light. D. The rose reflects red light.
The rose reflects red light.
Which of the following is not one of Kepler's laws of planetary motion? a) The orbit of each planet around the Sun is an ellipse with the Sun at one focus. b) As a planet orbits the Sun it sweeps out equal areas in equal times. c) The rotation of a planet is always aligned with its orbital motion around the Sun. d) Planets with larger orbits orbit the Sun at slower average speeds than planets with smaller orbits.
The rotation of a planet is always aligned with its orbital motion around the Sun
Why have more people seen an eclipse of the Moon than an eclipse of the Sun? a) Eclipses of the Sun are much rarer than eclipses of the Moon b) The shadow of the Moon is smaller than the shadow of Earth c) Anyone on the night side of Earth can see a total eclipse of the Moon d) B and C
The shadow of the Moon is smaller than the shadow of Earth and Anyone on the night side of Earth can see a total eclipse of the Moon
In binary stars, the orbital period depends on the masses of the stars and the sizes of the orbits. Why is this so valuable to know a) We can predict how long an orbit will take. b) This is the main way we determine the masses of stars. c) This lets us know if two stars that look close together in the sky really are in orbit.
This is the main way we determine the masses of stars.
Why are very high temperatures required for nuclear fusion to occur? a) It takes energy to make energy b) The two protons have + charges and repel. Only at high speed can they collide close enough for nuclear forces to bind them c) High temperature and speeds involve relativity, and this is a relativistic reaction d) They aren't. When fusion happens at room temperature it is called "cold" fusion
The two protons have + charges and repel. Only at high speed can they collide close enough for nuclear forces to bind them
Which of the following has to be true for an object that is speeding up? A. The net force and acceleration are in opposite directions B. The velocity and acceleration are in opposite directions C. The net force and velocity are in opposite directions D. The velocity and acceleration are in the same direction E. None of the above
The velocity and acceleration are in the same direction
Which of the following statements best reflects reality, as described by the peer-reviewed scientific literature? a) The world is warming, and human activity is the principle cause. b) The world is warming and natural variation is the principle cause. c) The world is warming and we don't yet have a good idea why. d) The world is not warming.
The world is warming, and human activity is the principle cause.
Why are smaller terrestrial bodies such as Mercury or the Moon "geologically dead"? a) They don't have volcanoes b) They cooled off faster than Earth did c) They don't have erosion d) They were hit by fewer meteorites e) They are made of different materials than Earth
They cooled off faster than Earth did
If the tilt of Earth's axis to its orbital plane was 40 degrees, instead of 23 ½, but its distance from the Sun remained the same, what would happen to the seasons? a) They would become less extreme-winter and summer would be more alike b) They would become more extreme-winter colder and summer warmer c) All of Earth would get colder d) All of Earth would get warmer
They would become more extreme-winter colder and summer warmer
If you had a very fast spaceship, could you travel to the celestial sphere in about a month? a) Yes, and the NASA Voyager spacecraft has already done so. b) No, the celestial sphere moves away from us at the speed of light so we can never catch up with it. c) No, the celestial sphere is so far away that, even moving at close to the speed of light, it would take tens of thousands of years to reach. d) This statement doesn't make sense because the celestial sphere is a concept and not a physical object
This statement doesn't make sense because the celestial sphere is a concept and not a physical object.
True or False: If you could go shopping on the Moon to buy a pound of chocolate, you'd get a lot more chocolate than if you bought a pound on Earth. a) True, because of the lower gravity on the Moon, it would take more chocolate to weigh a pound than on Earth. b) True, chocolate would have a lower density on the Moon and therefore more is needed to reach a pound in weight. c) False, a pound on the Moon is the same as a pound on Earth. d) False, chocolate weighs the same on the Moon as on Earth.
True, because of the lower gravity on the Moon, it would take more chocolate to weigh a pound than on Earth.
How does visible light compare to radio waves? a) Visible light is a form of light wave whereas radio waves are not. b) Radio waves are a form of electromagnetic wave whereas visible light is not. c) Visible light waves have a shorter wavelength than radio waves. d) Radio waves have a higher frequency than visible light waves. e) All of the above
Visible light waves have a shorter wavelength than radio waves.
Since the Sun's outer atmosphere or corona is millions of degrees but not very dense, a) We can't really see it b) We see it-it emits orange light and big flames c) We see X rays coming from it d) We only see the lower layers of the Sun's atmosphere, which are much more dense
We see X rays coming from it
If a planet travels in a circular orbit without speeding up or slowing down, is it accelerating? a) No b) Yes
Yes
Suppose we could magically replace Venus' actual atmosphere with an atmosphere identical to Earth's. Could liquid water exist on its surface? a) No, the runaway greenhouse effect would ensure that liquid water would immediately evaporate. b) No, the low pressure would ensure that liquid water would immediately evaporate. c) Yes, the surface temperature would be well below the boiling point of water. d) Yes, the conditions would be exactly as on Earth. e) Yes, but only at the poles e) Yes, but only at the poles
Yes, the surface temperature would be well below the boiling point of water.
Which of the following would most likely give off the most energy? A. a red star half the size (diameter) of the Sun B. a red star 10 times the size (diameter) of the Sun C. a blue star half the size (diameter) of the Sun D. a blue star 10 times the size (diameter) of the Sun
a blue star 10 times the size (diameter) of the Sun
Assume that intelligent aliens with radio transmitters and receivers are living on Proxima b. If we were to send them a message ("Hello world!"), how long would it take for us to hear back after the message is sent? A. ~4 years B. ~8 years C. ~20 years D. ~24 years
about 8 years
The wavelengths of emission lines from a gas depend on a) the electron energy levels of atoms in the gas. b) how ionized the gas is. c) the rotation and vibration energy levels of molecules in the gas. d) all of the above. e) none of the above
all of the above.
The gravitational attraction between an object and the Earth: A. stops just above the atmosphere B. extends to about half-way to the Moon C. stops beyond the Moon D. extends to infinity
extends to infinity
Which of the following would cause the force on the Moon by the Earth to increase by the largest amount? A. double the mass of the Moon. B. double the mass of Earth. C. move the moon two times closer to Earth. D. Due to Newton's third law, the Moon's force on Earth will always be the same size as the Earth's force on the Moon so none of the changes listed in choices a-c could cause the force to increase
move the moon two times closer to Earth
Light with a short wavelength a) has a lower frequency than light with a long wavelength. b) is redder than light with a long wavelength. c) has less energy than light with a long wavelength. d) all of the above e) none of the above
none of the above
If the distance between two objects is tripled, the gravitational force exerted by one on the other will be: A. one-third as much B. one-ninth as much C. three times as much D. nine times as much
one-ninth as much
The shorter the period of the Doppler curve, a) the closer the unseen planet is to the star. b) the farther the unseen planet is from the star. c) the greater the mass of the planet. d) the smaller the mass of the planet. e) A and C
the closer the unseen planet is to the star.
The larger the mass of the unseen planet, a) the larger the Doppler shift of the star. b) the smaller the Doppler shift of the star. c) the faster the period of the star's Doppler shift. d) the slower the period of the star's shift. e) A and C
the larger the Doppler shift of the star.
The speed of light is a) about 30,000 km/s. b) the product of its wavelength and its frequency. c) dependent on the strength of the electromagnetic field. d) all of the above
the product of its wavelength and its frequency
The higher the photon energy, A. the longer its wavelength. B. the shorter its wavelength. C. Energy is independent of wavelength
the shorter its wavelength
The orbital period of an unseen planet a) will be the same as period of the star's Doppler shift. b) will be much longer than the star's. c) will be much shorter than the star's
will be the same as period of the star's Doppler shift.