Massive Astronomy Exam 2 Study Set
Use the data in the table below to choose the correct description how escape velocity is related to properties of planets. Is the trend what you expect based on what you learned about escape velocity?
Escape velocity increases with increasing mass of planet. Such trend is expected, because escape velocity increases with increasing mass.
he solar nebula was 98 % ...
Hydrogen and helium.
In what direction does Uranus orbits the Sun?
It orbits the Sun in the same direction as the other planets.
Why is a sunflower yellow?
It reflects yellow light.
Which of the following is not true about the young Sun?
It was much brighter and hotter than it is today.
Suppose that two asteroids are orbiting the Sun on nearly identical orbits, and they happen to pass close enough to each other to have their orbits altered by this gravitational encounter. If one of the asteroids ends up moving to an orbit that is closer to the Sun, what happens to the other asteroid?
It will end up on an orbit that is farther from the Sun.
The only rocky planet to have more than one moon is
Mars
Compare your answer with the table below and name the planets that orbit just inside and outside Ceres's orbit.
Mars and Jupiter
About how old is the solar system?
4.5 billion years
According to modern scientific dating techniques, approximately how long ago did Earth and the other planets of our solar system form?
4.5 billion years
Why does a geostationary satellite must orbit Earth in 1 sidereal day, rather than 1 solar day?
Actual period of the Earth's rotation is sidereal day. Solar day is a bit longer because of the Earth's orbital motion.
"A star's 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets." This discovery would be inconsistent with the nebular theory because the theory holds that __________.
All the planets formed in a rotating, disk-shaped nebula
As you've seen, the nebular theory predicts that a cloud that gives birth to planets should have the shape of a spinning disk. Which observable property of our solar system supports this prediction?
All the planets orbit the Sun in the same direction and in nearly the same plane.
Which type is the Sun's visible-light spectrum, and why?
An absorption line spectrum. Relatively thin photosphere of the Sun absorbs the specific wavelength from the light emitted from the hot and dense interior of the Sun.
Choose the correct definition of an atom's atomic mass number.
An atom's atomic mass number is the number of protons plus the number of neutrons.
Choose the correct definition of an atom's atomic number.
An atom's atomic number is the number of protons it has in its nucleus.
As discussed in the Extraordinary Claims box, when the giant impact idea was first proposed, it was generally thought to be so unlikely that it wasn't seriously considered until decades later, after the Apollo missions to the Moon. What key piece of scientific understanding was missing that made it seem so unlikely when first proposed?
An understanding of the number and size of leftover planetesimals in the early solar system.
Where would you expect terrestrial planets to form in the solar nebula?
Anywhere between 0.3 AU and the frost line
The dwarf planet Eris was discovered in 2005, orbiting the Sun at an average distance about twice that of Pluto. In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system?
Both Pluto and Eris are smaller than any of the terrestrial planets. Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets. Both Pluto and Eris are less massive than any of the terrestrial or jovian planets.
Consider the three items from Part A that are not relevant to the giant impact hypothesis. As you'll learn in later chapters, the lack of volcanoes is a result of the Moon's relatively small size. But what explains the other two items — the Moon's synchronous rotation and gradually increasing distance from Earth?
Both are results of tidal interactions between the Moon and Earth.
Assume you have completed the two trials chosen in Part A. Which of the following possible outcomes from the trials would support Newton's theory of gravity? Neglect effects of air resistance.
Both balls fall to the ground in the same amount of time.
Assume you have completed the two trials chosen in Part A. Which of the following possible outcomes from the trials would support Newton's theory of gravity? Neglect effects of air resistance. Both balls fall to the ground in the same amount of time. The two balls take different amounts of time to reach the ground. The less massive ball takes longer to reach the ground. The more massive ball takes longer to reach the ground.
Both balls fall to the ground in the same amount of time.
How do the angular resolutions you found in parts A and B compare to the angular resolution of the Hubble Space Telescope? Comment on the challenge of making images of planets around other stars.
Both planets could be distinguished from the Sun in means of angular resolution. However, the light from planets could be lost in the glare of the Sun.
Consider the statement "There's no gravity in space." This statement is: Completely false. False if you are close to a planet or moon, but true in between the planets. Completely true.
Completely false.
Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.
Which of the following examples describes a situation where a car is experiencing a net force? The car is moving at constant speed. The car is making a gradual turn. The car is floating on a stationary boat. The car is stopped on a hill.
The car is making a gradual turn.
"Beyond its jovian planets, a star has two ice-rich objects as large as Mars." This discovery is consistent with the nebular theory, because this theory predicts that _________.
This might have happened in our own solar system if it had taken longer for the solar wind to clear the solar nebula
True or false... The mass of the Sun compared to the mass of all the planets combined is like the mass of an elephant compared to the mass of a cat.
True
Choose the correct conditions, under which two atoms are different isotopes of the same element.
Two atoms having the same number of protons and different numbers of neutrons.
Two hypothetical discoveries in Part A deal with moons that, like Earth's moon, are relatively large compared to their planets. Which of the following best explains why finding 1 planet with such a moon is consistent with the nebular theory, while finding 6 planets with such moons is not consistent?
Unusually large moons form in giant impacts, which are relatively rare events.
What best explains why finding 1 planet with such a moon is consistent with the nebular theory, while finding 6 planets with such moons is not consistent?
Unusually large moons form in giant impacts, which are relatively rare events.
_____________ has a rotational axis that is tilted so much it lies nearly in the plane of its orbit.
Uranus
Which planet is approximately halfway between Pluto's orbit and the Sun?
Uranus, the seventh planet from the Sun
Velocity
Velocity is used to describe how fast the object is moving and tells us in which direction it is going.
_____________ is the planet with the highest average surface temperature.
Venus
Describe the three key processes that led the solar nebula to take the form of a spinning disk. What observational evidence supports this scenario?
This cloud that formed the solar system began by collapsing under its own gravity. As it did so, to conserve angular momentum it spun faster. When clumps of gas and dust collided, both took velocities nearer the average. Since the average velocity tends to point along a flattened disk, the solar nebula eventually took on a disk shape. Evidence for these processes can be found in the fact that the planets orbit the Sun in nearly the same plane and in the same direction and that they spin in this same direction.
Suppose you have a camera attached to a telescope, and you want to record an image of a faint galaxy. Which of the following will help the most?
a lot of pixels and a long exposure time
Which technology can allow a single ground-based telescope to achieve images as sharp as those from the Hubble Space Telescope?
adaptive optics
How many of the planets orbit the Sun in the same direction that Earth does?
all
Which terrestrial planets have had volcanic activity at some point in their histories?
all of them
Consider the hypothetical discovery from Part A reading: "A star's 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets." This discovery would be inconsistent with the nebular theory because the theory holds that __________.
all the planets formed in a rotating, disk-shaped nebula
What type of visible light spectrum does the Sun produce?
an absorption line spectrum
Interferometry uses two or more telescopes to achieve:
an angular resolution equivalent to that of a much larger telescope.
Where would you expect terrestrial planets to form in the solar nebula?
anywhere between the innermost regions (within about the inner 0.3 AU) and the frost line
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: less than your normal weight at rest greater than your normal weight at rest equal to your normal weight at rest
greater than your normal weight at rest
How much greater is the light-collecting area of a 6-meter telescope than a 3-meter telescope?
four times
Today, scientists have a theory (the nebular theory) that explains all the major characteristics of the solar system. In science, we expect a theory like this not only to explain the observed characteristics of our solar system but also to predict __________.
general characteristics of other solar systems
As an interstellar gas cloud shrinks in size, its gravitational potential energy:
gradually transforms into other forms of energy.
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
Some nitrogen atoms have seven neutrons and some have eight neutrons; these two forms of nitrogen are
isotopes of each other.
If you see the color red in an X-ray image from the Chandra X-Ray Observatory, it means:
it depends: the colors are chosen arbitrarily to represent something about the X rays recorded by the telescope.
Which have more moons on average?
jovian planets
If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be:
one-quarter as strong.
The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________.
rocks, metals, and ices
What substances were found in the innermost regions (within about the inner 0.3 AU) of the solar system before planets began to form?
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
What substances were found within the inner 0.3 AU of the solar system before planets began to form?
Rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________.
Rocks, metals, ices, and hydrogen and helium gases
Are astroids rocky or icy?
Rocky
Home satellite dishes (such as those used for television) receive signals from communications satellites. Why do these satellites must be in geostationary orbit?
Satellite dishes do not have to track position of a geostationary satellite.
The planet with the lowest average density is
Saturn
This x-ray image was taken by the Chandra X-ray Observatory. Without knowing anything more about the object that is shown, what can you conclude from looking at this image?
Some parts of the object emit more x-rays than others.
Speed definition
Speed is used to describe how fast the object is moving.
When your eye forms an image, the _____ plays a role analogous to the detector in a camera.
retina
Moons cannot have atmospheres, active volcanoes, or liquid water.
false
Our Moon is about the same size as moons of the other terrestrial planets.
false
Saturn is the only planet in the solar system with rings.
false
We could probably learn more about Mars by sending a new spacecraft on a flyby than by any other method of studying the planet.
false
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
Suppose that two objects collide. Which of the following things is NOT the same both before and after the collision? the total angular momentum of the objects the total temperature of the objects the total energy of the objects the total momentum of the objects
the total temperature of the objects
As the cloud collapses, the overall force of gravity that draws the cloud inward __________ because __________. (Blank 1) gradually becomes stronger (Blank 1) gradually becomes weaker (Blank 1) stays constant at all times (Blank 2) the strength of gravity follows an inverse square law with distance (Blank 2) the mass of the cloud increases as it collapses (Blank 2) the total gravitational force is a conserved quantity
(Blank 1) gradually becomes stronger (Blank 2) the strength of gravity follows an inverse
As the cloud shrinks in size, its central temperature __________ as a result of its __________. (Blank 1) stays constant (Blank 1) decreases (Blank 1) increases (Blank 2) gravitational potential energy being converted to thermal energy (Blank 2) kinetic energy being converted to radiative energy (Blank 2) thermal energy being converted to radiative energy
(Blank 1) increases Blank 2) gravitational potential energy being converted to thermal energy
As the cloud shrinks in size, its rate of rotation __________ because __________. (Blank 1) slows down (Blank 1) speeds up (Blank 1) stays constant at all times (Blank 2) the force of gravity strengthens as the cloud shrinks (Blank 2) its total energy is conserved (Blank 2) its total angular momentum is conserved
(Blank 1) speeds up (Blank 2) its total angular momentum is conserved
Which of the following statements correctly state general principles of motion? (Assume that the moving object's mass is not changing.)
-Accelerated motion includes any motion involving a change in speed, change in direction, or both. -An object that is accelerating is also being acted upon by a (nonzero) net force. -An object that is accelerating is also undergoing a change in momentum.
Characteristics of the formation of jovian planets
-Accreted from icy planetesimals - Ejected icy planetesimals that are not Oort cloud comets -Formed in regions cold enough for water to freeze -Formed in a region of the solar system with lower orbital speeds -Large moons formed in surrounding disks of material
Which of the following correctly describe patterns of motion in the solar system? -The inner planets all rotate in the same direction (west to east) as Earth. -All the planets (not counting Pluto) have nearly circular orbits. -All the planets (not counting Pluto) orbit the Sun in nearly the same plane. -Inner planets orbit the Sun in the opposite direction from the outer planets. -The outer planets are so large that they nearly collide with each other on each orbit. -Planets closer to the Sun move around their orbits at higher speed than planets farther from the Sun.
-All the planets (not counting Pluto) have nearly circular orbits. -All the planets (not counting Pluto) orbit the Sun in nearly the same plane. -Planets closer to the Sun move around their orbits at higher speed than planets farther from the Sun.
While we may never be able to prove that our Moon really formed in a giant impact, which of the following would give scientists greater confidence that the model is correct? Select all that apply.
-Creating more sophisticated models of the giant impact that correctly predict many detailed characteristics of the Earth and Moon. -Finding evidence that other giant impacts occurred in our solar system, with a total number of impacts consistent with what models of solar system formation lead us to expect. -Observing evidence of recent giant impacts in other solar systems that are currently in the process of formation.
Characteristics of Jovian planets
-Extensive ring systems -Numerous orbiting moons -Low average density -Primarily composed of hydrogen, helium, and hydrogen compounds
Based on the nebular theory as it explains our own solar system, which of the following should we expect to be true for other star systems?
-Jovian planets always form farther from their star than terrestrial planets. -Planetary systems should generally have all planets orbiting in nearly the same plane. -Many extrasolar planets should fall into the terrestrial or jovian categories. -Planetary systems should be common.
Based on the nebular theory as it explains our own solar system, what should we expect to be true for other star systems?
-Planetary systems should generally have all planets orbiting in nearly the same plane. -Jovian planets always form farther from their star than terrestrial planets. -Planetary systems should be common. -Other planetary systems should have the same two types of planets: terrestrial and jovian.
Characteristics of Terrestrial planets
-Solid and rocky surface -Small size -Located within the inner solar system
Characteristics of the formation of terrestrial planets
-Surfaces dramatically altered during the heavy bombardment -Accreted from planetesimals of rock and metal
Large telescopes often have small fields of view. For example, the Hubble Space Telescope's (HST's) advanced camera has a field of view that is roughly square and about 0.06 degree on a side. Calculate the angular area of the HST's field of view in square degrees.
0.0036 square degrees
Four materials that made up the solar nebula, ranked from the most abundant in the solar nebula to least abundant.
1. Hydrogen and helium gas 2. Hydrogen compounds 3. Rock 4. Metals
Stages that occurred during thee formation of our solar system first to last
1. Large cloud of gas and dust 2. Contraction of solar nebula 3. Condensation of solid particles 4. Accretion of planetesimals 5. Clearing the solar nebula
Rank the four materials based on the temperature at which each would condense into a solid, from highest to lowest
1. Metals 2. Rock 3. Hydrogen compounds 4. Hydrogen and helium gas
Which object has more gravitational potential energy, a 100-kilogram satellite orbiting Jupiter or a 100-kilogram satellite orbiting Earth. (Assume both satellites orbit at the same distance from their planets' center.) ? How do you know?
100-kilogram satellite orbiting Jupiter because the satellite in Jupiter orbit has more gravitational potential energy because Jupiter's stronger gravity means that the satellite, if it fell, would fall at a greater speed and hence have more kinetic energy. Since energy must be conserved, the satellite must also have more gravitational potential energy.
Suppose that the Sun were to collapse from its current radius of about 700,000 km to a radius of only about 6000 km (about the radius of Earth). What would you expect to happen as a result?
A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more rapidly.
Choose the correct description of an object that is accelerating: -A car traveling on a straight, flat road at 50 miles per hour. -A car going around a circular track at a steady 100 miles per hour -A car traveling on a straight uphill road at 30 miles per hour.
A car going around a circular track at a steady 100 miles per hour
Which person is weightless?
A child in the air as she plays on a trampoline.
Which person is weightless? A child in the air as she plays on a trampoline. A scuba diver exploring a deep-sea wreck. An astronaut on the Moon.
A child in the air as she plays on a trampoline.
The verdict at the end of the Extraordinary Claims box says "Likely correct, though may never be possible to prove definitively." In the context of models, which of the following best explains this verdict?
A model that precisely reproduces major characteristics of the Moon would seem likely correct, but we can't go back in time to see that it actually happened that way.
Choose the correct definition of a molecule.
A molecule is a group of two or more atoms bound together.
Why does a geostationary satellite must orbit around Earth's equator, rather than in some other orbit (such as around the poles)?
A satellite on non-equatorial orbit would show daily motion even if its period is exactly 1 sidereal day.
The diffraction limit is a limit on:
A telescope's angular resolution.
Suppose that the Sun were to collapse from its current radius of about 700,000 km to a radius of only about 6000 km (about the radius of Earth). What would you expect to happen as a result? A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more rapidly. A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more slowly. Both the total amount of energy and the rotation rate would remain the same. The Sun would gain more energy and more angular momentum.
A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin much more rapidly.
Acceleration
Acceleration is the rate of change of velocity in time.
How did planet formation lead to the existence of asteroids and comets?
Asteroids and comets are essentially leftovers from planet formation. They are bits of material that were never swept up into planets, but probably could have been. We find asteroids in the inner solar system (between Mars and Jupiter, mainly) because near the center of the disk it was too hot for the hydrogen compounds to freeze and participate in planet formation. Farther out, where the ices were able to condense, the small bodies were icy. And so we have comets.
If you actually performed and compared the two trials chosen in Part C, you would find that, while the basketball and marble would hit the ground at almost the same time, it would not quite be exact: The basketball would take slightly longer to fall to the ground than the marble. Why?
Because air resistance has a greater effect on the larger ball.
If you actually performed and compared the two trials chosen in Part C, you would find that, while the basketball and marble would hit the ground at almost the same time, it would not quite be exact: The basketball would take slightly longer to fall to the ground than the marble. Why? Because air resistance has a greater effect on the larger ball. Because air resistance has a greater effect on the smaller ball. Because gravity has a greater effect on the larger ball. Because gravity has a greater effect on the smaller ball.
Because air resistance has a greater effect on the larger ball.
Which object has more gravitational potential energy, a bowling ball perched on a cliff ledge or a baseball perched on the same ledge? How do you know?
Bowling ball because at the same height, a more massive object has more gravitational potential energy than a less massive object. The reason is that both objects will fall at the same rate due to gravity, but the more massive object will have more kinetic energy at any particular speed. Thus, the more massive object must also have more gravitational potential energy, since its total (kinetic plus gravitational potential) energy is conserved as it falls.
Each diagram shows a single experimental trial in which you will drop a ball from some height. In each case, the ball's size, mass, and height are labeled. Note that two diagrams show a basketball, one diagram shows a bowling ball of the same size but larger mass, and one diagram shows a much smaller marble with the same mass as the basketball. You have a timer that allows you to measure how long it takes the ball to fall to the ground. Which pair of trials will allow you to test the prediction that an object's mass does not affect its rate of fall? Choice One: mass = .5kg, size = marble, height = 30m Choice Two: mass = .5kg, size = basketball, height = 30m Choice Three: mass = 5.0kg, size = bowling ball, height = 20m Choice Four: mass = .5kg, size = basketball, height = 20m
Choice Three and Choice Four
Consider again the experimental trials from Part A. This time, you wish to test how the size of an object affects the rate of its fall. Which pair of trials should you compare? Choice One: mass= 5.0kg, size= bowling ball, height = 20m Choice Two: mass = 0.5kg, size = marble, height = 30m Choice Three: mass = 0.5kg, size = basketball, height = 30m
Choice Two and Choice Four
Rank pluto, jupiter, earth, mercury, mars, and saturn from closest to farthest from the sun.
Closest: Mercury Earth Mars Jupiter Saturn Farthest:Pluto
The nebular theory also predicts that the cloud will flatten into a disk as it shrinks in size. Which of the following best explains why the collapsing cloud should form a disk?
Colliding cloud particles exchange angular momentum and, on average, end up with the rotation pattern for the cloud as a whole.
What do we mean by comparative planetology? Does it apply only to planets?
Comparative planetology is a way of studying the solar system that relies on comparing the objects in the solar system to each other. The objects do not need to be planets; moons, rings, asteroids, and comets are all part of the field, for example.
Suppose we want to know what the Sun is made of. What should we do?
Compare the wavelengths of lines in the Sun's spectrum to the wavelengths of lines produced by chemical elements in the laboratory.
Consider the statement "There's no gravity in space." This statement is:
Completely false.
Which of the following did not occur during the collapse of the solar nebula?
Concentrating denser materials nearer the Sun
Why do dishes that aren't themselves heated by the microwave oven sometimes still get hot when you heat food on them? (Note: It's not a good idea to put empty dishes in a microwave.)
Conduction from heated food heats the dish.
Are these statements consistent with the nebular theory or inconsistent? -A star is surrounded by a disk of gas but has no planets -A star has 20 planets -Of a stars 5 terrestrial planets, 1 has a moon as large as earths moon -Beyond its jovian planets, a star has two ice rich objects as large as Mars
Consistent with the nebular theory
Which object has more gravitational potential energy, a diver on a 10-meter platform or a diver on a 3-meter diving board?
Diver on a 10-meter platform because the diver has more gravitational potential energy on the higher board because she has a greater distance that she can fall.
Rank pluto, jupiter, earth, mercury, mars, and saturn based on their mass, from highest to lowest.
Highest: Sun Jupiter Earth Mars Mercury Lowest: Pluto
Part E Einstein's theory, like Newton's, predicts that, in the absence of air resistance, all objects should fall at the same rate regardless of their masses. Consider the following hypothetical experimental results. Which one would indicate a failure of Einstein's theory? - Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates.
Dropping the balls on the Moon removes any potential effects due to air resistance, so a result in which mass affects the rate of fall would directly contradict the prediction of Einstein's theory.
Most of the surface of ________ is covered with liquid water.
Earth
The largest terrestrial planet
Earth
According to the law of universal gravitation, what would happen to Earth if the Sun were somehow replaced by a black hole of the same mass?
Earth's orbit would not change.
According to the law of universal gravitation, what would happen to Earth if the Sun were somehow replaced by a black hole of the same mass? Earth would be quickly sucked into the black hole. Earth would slowly spiral in to the black hole. Earth's orbit would not change.
Earth's orbit would not change.
Under what circumstances can energy level transitions occur?
Electrons can make a transition from one level to another by taking in or emitting a specific amount of energy. If too much or too little energy is offered, the electron cannot make the transition.
Comte was proven wrong in his claim that we could never learn the composition of stars. What do we know today that Comte did not know when making his claim, and that makes it possible for us to learn the chemical compositions of stars?
Every chemical element produces a unique spectral fingerprint.
True or false.... Our Moon is about the same size as moons of the other terrestrial planets.
False
True or false: Venus has no oceans, so it could not have tides even if it had a moon (which it doesn't).... Explain your answer.
False. This statement does not make sense, because tides affect an entire planet, not just the oceans. Thus, if Venus had a moon, it could have "land tides."
Rank metals, rock, and hydrogen compounds based on the distance from the Sun at which they could condense into a solid in the solar nebula, from farthest to closest.
Farthest: Hydrogen compounds Rock Closest: Metals
If you want to make a rocket turn left, you need to: Fire an engine that shoots out gas to the left. Fire an engine that shoots out gas to the right. Spin the rocket clockwise.
Fire an engine that shoots out gas to the right.
Suppose you are aboard a rocket that is orbiting Earth in the low, circular orbit shown. If you want to escape from Earth and head to the Moon or Mars along the "escape" path shown, what do you need to do?
Fire the rocket engine in your direction of travel, so that you gain speed.
What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in the Space Station.
Free-fall is the state of falling without any resistance to the fall. Objects in free-fall are weightless because they are not pushing against anything to give them weight. Astronauts in the Space Station are in constant free-fall as they fall around the Earth (always missing it), so they are weightless.
Considering only the two objects shown in each pair, rank the strength, from strongest to weakest, of the gravitational force acting on the asteroid on the left.: The pairs: asteroid and moon, asteroid and asteroid, asteroid and sun, asteroid and hydrogen atom, asteroid and earth
From Strongest to Weakest: asteroid and Sun asteroid and Earth asteroid and Moon asteroid and asteroid asteroid and hydrogen atom
As you watch the video, notice that the size of the tidal bulges varies with the Moon's phase, which depends on its orbital position relative to the Sun. Which of the following statement(s) accurately describe(s) this variation?
High tides are highest at both full moon and new moon. Low tides are lowest at both full moon and new moon.
Rank mars, jupiter, earth, and mercury based on the number of moons that orbit them, from highest to lowest.
Highest: Jupiter Mars Earth Lowest: Mercury
Rank mercury, earth, mars, neptune, and jupiter based on their average surface (or cloud-top) temperature, from highest to lowest.
Highest: Mercury Earth Mars Jupiter Lowest: Neptune
The solar system has two types of planets, terrestrial and jovian. According to the nebular theory, why did terrestrial planets form in the inner solar system and jovian planets in the outer solar system?
Ices condensed only in the outer solar system, where some icy planetesimals grew large enough to attract gas from the nebula, while only metal and rock condensed in the inner solar system, making terrestrial planets.
Are comets rocky or icy?
Icy
How do the spectra of the different types of light bulbs compare?
Incandescent light bulbs emit generally continuous thermal spectra. CFLs and LEDs emit the light in the broad bands near specific wavelengths.
Why CFLs and LEDs can be much more energy efficient than incandescent bulbs?
Incandescent light bulbs emit most of consumed energy in infrared wavelengths. CFLs and LEDs transfer almost all consumed energy to visible light.
Are these statements consistent with the nebular theory or inconsistent? -All 6 of a stars terrestrial planets have a moon as large as earths moon -A stars 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets -A star has 9 planets, but none orbit in close to the same plane -A stars 4 jovian planets formed in its inner solar system and its 4 terrestrial planets formed farther out
Inconsistent with the nebular theory
Why is Newton's version of Kepler's third law so useful to astronomers? It allows us to calculate distances to distant objects. It can be used to determine the masses of many distant objects. It explains why objects spin faster when they shrink in size. It tells us that more-distant planets orbit the Sun more slowly.
It can be used to determine the masses of many distant objects
What is the leading hypothesis for the origin of the Moon?
It formed from the material ejected from Earth in a giant impact.
Suppose that two asteroids are orbiting the Sun on nearly identical orbits, and they happen to pass close enough to each other to have their orbits altered by this gravitational encounter. If one of the asteroids ends up moving to an orbit that is closer to the Sun, what happens to the other asteroid? It will stay on its original orbit. It will also end up on an orbit that is closer to the Sun. It will become much cooler. It will end up on an orbit that is farther from the Sun.
It will end up on an orbit that is farther from the Sun.
What's unusual about our Moon?
It's surprisingly large relative to the planet it orbits.
Do jovian or terrestrial planets have shorter days?
Jovian
The largest jovian planet
Jupiter
____________ is the jovian planet that orbits closest to the Sun.
Jupiter
Choose the correct definition and two examples of kinetic energy.
Kinetic energy is the energy an object has due to its motion. A car driving down the highway or molecules of hot, raising up air have kinetic energy.
Choose the correct definition and two examples of kinetic energy. Kinetic energy is the energy an object has due to its position. Two examples are a car resting on the hill or the movements of the molecules of liquid in a cup of hot coffee. Kinetic energy is the energy an object has due to its motion. Two examples are a car driving down the highway or the movements of the molecules of liquid in a cup of hot coffee. Kinetic energy is the energy an object has due to its motion. Two examples are a car resting on the hill or the movements of the molecules of liquid in a cup of hot coffee. Kinetic energy is the energy an object has due to its position. Two examples are a car driving down the highway or the movements of the molecules of liquid in a cup of hot coffee.
Kinetic energy is the energy an object has due to its motion. Two examples are a car driving down the highway or the movements of the molecules of liquid in a cup of hot coffee.
For the purposes of seeking a theory to explain the formation of the solar system, we identify four major features of our solar system. Which of the following represent these four major features?
Large bodies in the solar system have orderly motions. Several exceptions to the general trends stand out. Planets fall into two major categories (terrestrial and jovian). Swarms of asteroids and comets populate the solar system.
Rank pluto, jupiter, earth, mercury, mars, and saturn based on their size from largest to smallest.
Largest: Sun Jupiter Earth Mars Mercury Smallest:Pluto
Why do we say that light is an electromagnetic wave? What is the relationship among wavelength, frequency, and speed for light?
Light is a vibration of electric and magnetic fields. ν=cλ
Suppose Earth had a second moon, called Swisscheese, with an average orbital distance double the Moon's and a mass about the same as the Moon's. Is Swisscheese's orbital period longer or shorter than the Moon's? Explain.
Longer because by Newton's version of Kepler's third law, more distant objects have longer orbital periods.
The planet that orbits closest to the Sun is
Mercury
Many "leftovers" from planetary formation were likely ejected from our solar system, and the same has presumably happened in other star systems. Given that fact, should we expect to find meteorites that come from other star systems? How rare or common would you expect them to be? (Be sure to consider the distances between stars.) Suppose that we did find a meteorite identified as a leftover from another stellar system. What could we learn from it?
Meteorites from another solar system are possible, but very rare. Stars are very far apart, and it would take a "lucky shot" for a comet or asteroid to be ejected from one solar system and strike a planet in ours. However unlikely, scientists are always on the lookout for such a find. Among other things, we'd learn when their solar system formed, and from what ingredients.
Why doesn't a microwave oven make a plastic dish get hot?
Microwave ovens are tuned to emit frequencies absorbed by water molecules, not by a plastic dish.
Define momentum and force. What do we mean when we say that momentum can be changed only by a net force?
Momentum is the product of mass and velocity (mass * velocity). A force is something that can change the momentum of an object. However, the object's momentum will respond only to a net force, the force that is left when we add all of the forces together. Even if the individual forces are large, if they cancel out and leave no net force, then there is no change in momentum.
Suppose our solar nebula had begun with much more angular momentum than it did. Do you think planets could still have formed? Why or why not? What if the solar nebula had started with zero angular momentum?
More than one correct answer: On one hand, more angular momentum might force more material into the solar nebula (instead of into the protosun). In this scenario, more planets or more massive ones might form. On the other hand, too much angular momentum might result in two protostars, possibly destabilizing the planet-forming process. With no angular momentum, the entire nebula would collapse into a star, with no disk from which to make planets.
What fraction of the large moons of the planets orbit in the same direction as their planets rotate?
Most
This diagram shows the approximate depths to which different wavelengths of light penetrate Earth's atmosphere. Why does it show an airplane?
Much of the infrared spectrum can be observed from an airplane that flies above most clouds.
__________ is about 30 times as far from the Sun as our own planet.
Neptune
Could hydrogen and helium gas condense into solid form under the conditions that exist in interstellar clouds such as the solar nebula?
Never
Summarize the universal law of gravitation both in words and with an equation.
Newton's law of universal gravitation states that every object in the universe attracts every other object. The force of the attraction depends on the product of the masses and decreases as 1 over the distance between the objects squared. In mathematical form: F_g = F*M_1*M_2/d^2 where F_g is the force of gravity, G is the gravitational constant, M_1 and M_2 are the masses of the objects, and d is the distance separating the centers of the objects.
Part B Assume you have completed the two trials chosen in Part A. Which of the following possible outcomes from the trials would support Newton's theory of gravity? Neglect effects of air resistance. - Both balls fall to the ground in the same amount of time.
Newton's theory of gravity predicts that, in the absence of air resistance, all objects on Earth should fall with the same acceleration of gravity, regardless of mass. This means that balls dropped from the same height should take the same amount of time to reach the ground.
What substances existed as solid flakes within the inner 0.3 AU of the solar system before planets began to form?
None
As shown in the video, Earth has two tidal bulges at all times. Approximately where are these bulges located?
One faces the Moon and one faces opposite the Moon.
Suppose that two stars are separated in the sky by 0.1 arcsecond. Choose the correct statement describing, what will you see if you look at them with a telescope that has an angular resolution of 0.5 arcsecond.
One point of light that is the blurred image of both stars.
Briefly describe the patterns of motion that we observe among the planets and moons of our solar system.
Orderly motions in the solar system are • Planets all orbit in nearly the same plane and have nearly circular orbits. • Planets orbit the Sun in the same direction. • Most planets spin in the same direction as they orbit. • Most of the large moons in the solar system also orbit in the same sense as the planets—in nearly circular orbits, generally in nearly the same plane.
Which of the following procedures would allow you to make a spectrum of the Sun similar to the one shown, though with less detail?
Pass a narrow beam of sunlight through a prism.
Why do the observed patterns of motion lead to the conclusion that the planets were not born in separate, random events?
Planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane
Are there any planets for which you would expect the surface temperature to vary significantly over the course of each orbit? Explain.
Planets with different min/max distances (i.e., significant eccentricities) will have temperature variations due to changing distance from the Sun: Mercury, Mars, and Pluto.
Which planets would you expect not to have seasons? Why?
Planets with small axis tilts will not have seasons: Mercury, Venus, Jupiter.
Choose the correct definition and two examples of potential energy.
Potential energy is energy that is stored. Two examples are mechanical energy in a compressed spring and gravitational energy in a rock on the top of a hill.
Choose the correct definition and two examples of potential energy. Potential energy is energy of close molecules interaction. Two examples of potential energy are breakfast cereal, which has chemical potential energy, and a heavy book on the top shelf at the library, which has gravitational potential energy. Potential energy is energy that is stored. Two examples of potential energy are molecules of liquid in a cup of hot coffee, and a heavy book on the top shelf at the library, which has gravitational potential energy. Potential energy is energy that is stored. Two examples of potential energy are breakfast cereal, which has chemical potential energy, and a heavy book on the top shelf at the library, which has gravitational potential energy. Potential energy is energy of close molecules interaction. Two examples of potential energy are molecules of liquid in a cup of hot coffee, and a heavy book on the top shelf at the library, which has gravitational potential energy.
Potential energy is energy that is stored. Two examples of potential energy are breakfast cereal, which has chemical potential energy, and a heavy book on the top shelf at the library, which has gravitational potential energy.
Choose the correct definition and two examples of potential energy. Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves. Radiative energy is energy of oscillation. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves. Radiative energy is energy of oscillation. Sunlight carries this form of energy, as do other forms of light including X-rays and acoustic waves. Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and acoustic waves.
Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves.
Choose the correct definition and two examples of radiative energy. Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves. Radiative energy is energy of oscillation. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves. Radiative energy is energy of oscillation. Sunlight carries this form of energy, as do other forms of light including X-rays and acoustic waves. Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and acoustic waves.
Radiative energy is energy in light. Sunlight carries this form of energy, as do other forms of light including X-rays and radio waves.
Choose the correct definition and two examples of radiative energy.
Radiative energy is energy in the form of light. Sunlight and radio waves carry this form of energy.
Would this be reasonable or surprising.... A solar system has 12 planets that all orbit the star in the same direction and in nearly the same plane. The 15 largest moons in this solar system orbit their planets in nearly the same direction and plane as well. However, several smaller moons have highly inclined orbits around their planets. Why?
Reasonable because this statement makes sense and in fact is similar to the situation in our solar system.
This diagram represents the solar nebula early in its history and shows the location of the frost line. Suppose you discover an object that is made of metal, rock, and ice. In which of the four regions shown in the diagram did it form?
Region 4
Einstein's theory, like Newton's, predicts that, in the absence of air resistance, all objects should fall at the same rate regardless of their masses. Consider the following hypothetical experimental results. Which one would indicate a failure of Einstein's theory?
Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates.
Einstein's theory, like Newton's, predicts that, in the absence of air resistance, all objects should fall at the same rate regardless of their masses. Consider the following hypothetical experimental results. Which one would indicate a failure of Einstein's theory? Scientists dropping balls from the Leaning Tower of Pisa find that balls of different size but the same mass fall at slightly different rates. Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates. Scientists dropping balls from the Leaning Tower of Pisa find that balls of different mass but the same size fall at slightly different rates.
Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates.
Rank mercury, earth, mars, neptune, and jupiter based on the amount of time it takes them to orbit the Sun, from shortest to longest.
Shortest: Mercury Earth Mars Jupiter Longest: Neptune
Why do some clay dishes get hot in the microwave?
Some clay dishes contain some water inside them.
Would this be reasonable or surprising.... A solar system has 10 planets that all orbit the star in approximately the same plane. However, five planets orbit in one direction (e.g., counterclockwise), while the other five orbit in the opposite direction (e.g., clockwise). Why?
Surprising because the nebular theory cannot explain a "backward" planet, as all planets should form from the "forward"-moving nebula. A planet could conceivably be captured into such an orbit, if a planet ejected from another star system somehow entered our own solar nebula and was slowed down. This process is analogous to the capture of a retrograde satellite in a jovian nebula. However, it is extremely unlikely that half the planets in a solar system would have been captured in this way.
Describe how tides would differ due to the presence of this second moon. Consider the cases when the two moons are on the same side of Earth, on opposite sides of Earth, and 90∘ apart in their orbits.
Swisscheese would create a third tidal bulge on the Earth. When the moons were on the same side of the Earth or on opposite sides, these bulges would add together to create extra large tides. When they were 90 degrees apart, the bulges would partially cancel, creating smaller tides. When the moons were lined up in their new or full phases, the bulges they raised would also add with the tidal bulge due to the Sun, creating extra large tides.
What regions of the solar system are comets and astroid concentrated in?
The Kuiper belt The Oort cloud The astroid belt
Explain how the Moon creates tides on Earth. Why do we have two high and low tides each day?
The Moon creates tides on the Earth by pulling on the different parts of Earth with different forces. The nearest parts of the Earth get stronger tugs, according to Newton's law of universal gravitation, so they try to move more toward the Moon than the farther-away parts. This actually creates two bulges: The nearest point to the Moon bulges toward the Moon because it is more attracted to the Moon than the average part of the planet, while the farthest point bulges away because it is less attracted to the Moon than the average part of the planet. This leads to two high and two low tides each day as we spin around under the Moon.
Which of the following best describes why the Sun's spectrum contains black lines over an underlying rainbow?
The Sun's hot interior produces a continuous rainbow of color, but cooler gas at the surface absorbs light at particular wavelengths.
What is the acceleration of gravity?
The acceleration of gravity, g, is the acceleration downward due to gravity, which is about 10 m/s^2 (more precisely, 9.8 m/s^2).
The "extraordinary" part of Comte's claim was his statement that we could never learn the composition of stars. Which of the following best summarizes the key lesson we should learn from the fact that his claim was ultimately proven wrong?
The advance of science and technology may someday provide ways to answer questions that seem unanswerable today.
Describe the laws of conservation of momentum, angular momentum, and energy. Give an example of how each is important in astronomy.
The conservation laws say that momentum, angular momentum, and energy are all conserved. That is, in a particular system, the total amount of each of these quantities does not change. An example of conservation of momentum in astronomy is a rocket. If we start with a rocket at rest and fire the engines, the rocket expels a lot of hot gas out the back. To conserve momentum, the rocket must move forward. Conservation of angular momentum is what gives us Kepler's second law: When a planet gets closer to the Sun, it has to move faster to keep its angular momentum the same as when it is farther from the Sun, when it moves slower. Conservation of energy tells us that as an object falls to Earth's surface, it loses gravitational potential energy. To conserve energy, the object has to move faster as it falls. Eventually, it hits the ground and stops. At this point, its kinetic energy is converted to heat and sound.
The diagram represents energy levels in a hydrogen atom. The labeled transitions (A through E) represent an electron moving between energy levels. If an electron at level 1 in a hydrogen atom absorbs 10.2 eV of energy, it moves to level 2. What typically happens next?
The electron returns to level 1 by emitting an ultraviolet photon with 10.2 eV of energy.
In Part A, you found that your weight will be greater than normal when the elevator is moving upward with increasing speed. For which of the following other motions would your weight also be greater than your normal weight?
The elevator moves downward while slowing in speed.
In Part A, you found that your weight will be greater than normal when the elevator is moving upward with increasing speed. For which of the following other motions would your weight also be greater than your normal weight? The elevator moves upward with constant velocity. The elevator moves upward while slowing in speed. The elevator moves downward with constant velocity. The elevator moves downward while increasing in speed. The elevator moves downward while slowing in speed.
The elevator moves downward while slowing in speed.
What was the frost line? Which ingredients condensed inside and outside the frost line? What role did it play in the formation of two distinct types of planets?
The frost line is the point moving away from the Sun where it is cool enough for hydrogen compounds to freeze. Since the solar nebula was hotter near the center of the disk, hydrogen compounds such as water stayed gaseous in the inner solar system. Outside of the frost line, they froze. As a solid, it was able to participate in building planets. Since there was so much more water (and, farther out, solid ammonia and methane) in the nebula, the forming planets past the frost line were much larger than the ones inside that limit. Furthermore, this large size of the "jovian planet seed" allowed it to gather hydrogen/helium gas and make truly He planets.
Part D If you actually performed and compared the two trials chosen in Part C, you would find that, while the basketball and marble would hit the ground at almost the same time, it would not quite be exact: The basketball would take slightly longer to fall to the ground than the marble. Why? - Because air resistance has a greater effect on the larger ball.
The larger size and lower density of the basketball means it will encounter more air resistance than the marble, so it will take slightly longer to reach the ground.
What physical law explains why a cloud will rotate rapidly as it collapses?
The law of conservation of angular momentum
The nebular theory also predicts that the cloud should heat up as it collapses. What physical law explains why it heats up?
The law of conservation of energy
What is the nebular theory, and why is it widely accepted by scientists today?
The nebular theory states that the solar system formed from a collapsing cloud of gas and dust billions of years ago. It is widely accepted by scientists today because it explains the properties of the solar system remarkably well. However, there is not observational evidence of other forming solar systems to support this theory.
Consider only the first major feature, which concerns observed patterns of motion in the solar system. Scientifically, which of the following possible conclusions is justified from the patterns of motion alone?
The planets were not each born in a separate, random event.
Would the order of the ranking for the different forms of light listed in Part A be different if you were ranking the frequency of the different forms of light (lowest to highest, left to right)? What if the ranking is done for the wavelengths of the different forms of light (shortest to longest, left to right)?
The ranking by frequency would have the same order, since energy is directly proportional to frequency. The ranking by wavelength would have the opposite order, because frequency and wavelength are inversely related.
One tidal bulge faces toward the Moon because that is where the gravitational attraction between Earth and the Moon is strongest. Which of the following best explains why there is also a second tidal bulge?
The second tidal bulge arises because gravity weakens with distance, essentially stretching Earth along the Earth-Moon line.
Explain why you can't feel this tidal force.
The tidal force acting on you depends on the difference between the gravitational force acting on your head and on your toes. But the gravitational force on any part of your body depends on the distance of the body part from the center of the Earth. Because the length of your body is negligible compared to the radius of the Earth, there's no noticeable difference in gravitational force between your head and your toes. (As discussed in Chapter The Bizarre Stellar Graveyard, this would no longer be the case if you could stand on a very compact object such as a neutron star, or if you were falling into a black hole.)
Part A Each diagram shows a single experimental trial in which you will drop a ball from some height. In each case, the ball's size, mass, and height are labeled. Note that two diagrams show a basketball, one diagram shows a bowling ball of the same size but larger mass, and one diagram shows a much smaller marble with the same mass as the basketball. You have a timer that allows you to measure how long it takes the ball to fall to the ground. Which pair of trials will allow you to test the prediction that an object's mass does not affect its rate of fall? - mass:5.0kg ; size:bowling ball ; height:20m - mass:5.0kg ; size:basketball ; height:20m
The simplest way to test the effects of mass is to compare the results of two trials that are identical except for the mass of the balls. In the language of experimental design, we say that the mass is the "variable of interest" for this experiment, and we therefore hold the other variables (size and height) constant so that they cannot affect the results.
Which of the following is not one of the four major features of the solar system?
The solar system contains eight planets plus dwarf planets (including Ceres, Pluto, and Eris).
Choose the correct explanation why does the following statement make sense (or is clearly true) or does not make sense (or is clearly false): "I've never been to space, so I've never experienced weightlessness."
The statement does not make sense. Any person can experience weightlessness on Earth, it just requires long enough free-fall.
Which of the following is not a reason why telescopes tend to be built on mountaintops that are relatively far from cities and are in regions with dry climates?
The thin air on mountaintops makes the glass in telescope mirrors less susceptible to warping.
The Moon has been gradually migrating outward from Earth over the past few billion years Should Earth's tides long ago have been larger, smaller, or remained the same?
The tides should have been larger. As distance decreases,gravitational force increases. So the stretching force would have been larger.
Part C Consider again the experimental trials from Part A. This time, you wish to test how the size of an object affects the rate of its fall. Which pair of trials should you compare? - mass:0.5kg ; size:marble ; height:30m - mass:0.5kg ; size:basketball ; height:30m
The variable of interest is now size, so appropriate trials to compare are those in which size differs but other variables are constant.
This photo shows a single star photographed by the Hubble Space Telescope. Why doesn't the star appear as a single, sharp point of light?
The wave properties of light make this type of blurring an unavoidable feature of any telescope.
If an astronaut goes on a space walk outside the Space Station, she will quickly float away from the station unless she has a tether holding her to the station. Choose the correct explanation why does the statement make sense (or is clearly true) or does not make sense (or is clearly false).
This statement is false. She and the Space Station share the same orbit and will stay together unless they are pushed apart.
If a distant galaxy has a substantial redshift (as viewed from our galaxy), then anyone living in that galaxy would see a substantial redshift in a spectrum of the Milky Way Galaxy. Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false).
This statement makes sense. The redshift means that we see the galaxy moving away from us, so observers in that galaxy must also see us moving away from them—which means they see us redshifted as well.
What is tidal friction? What effects does it have on Earth? How does it explain the Moon's synchronous rotation?
Tidal friction is the loss of spin energy due to the movement of the tidal bulges. This friction causes Earth's rotation to slow gradually with time. To conserve angular momentum in this process, the Moon gradually moves farther from Earth. In the case of Earth, tidal friction hasn't slowed us down to the point where we keep the same face pointing toward the Moon. However, tidal friction long ago made the Moon slow down to that point. This is the cause of its synchronous rotation.
Are there any exceptions to the rule that planets rotate with small axis tilts and in the same direction that they orbit the Sun?
Venus and Uranus are exceptions.
What do we mean when we say that energy levels are quantized in atoms?
We mean that the electrons can have only discrete values of electrical potential energy in atoms.
What is the leading hypothesis for the Moon's formation, and what evidence supports this hypothesis?
We think that the Moon formed when a large impactor struck Earth with a glancing blow. Such a collision would have blown a lot of material into orbit around Earth, temporarily forming a disk around our planet. From this disk, the Moon formed. Evidence in favor of this theory includes the chemical composition of the Moon: It is similar to Earth's mantle (which is where the material probably came from) and it is deficient in easily vaporized compounds like water. It is not really surprising that such an event could have affected Earth. There are other objects in the solar system that seem to show the effects of similar collisions. Uranus is tipped over. Pluto is both tipped over and has a large moon like we do. Mercury lacks most of the outer layers we would expect it to have, which might have been blasted off in a collision. Astronomers also believe they have detected the thermal radiation from the dust of a comparable impact around another star.
Suppose the Moon had rotated more slowly when it formed than it does now.... Would it still have ended up in synchronous rotation? Why or why not?
Yes because if the Moon had rotated more slowly when it formed, the tidal forces would have acted to speed its rotation up until the rotation became synchronized with the orbit.
Could such a reactor power the entire United States with the water flowing from your kitchen faucet? Assume that it takes you 15 seconds to fill the 1.5-liter kettle.
Yes, and it would even have energy to spare.
Most people are familiar with the rise and fall of ocean tides. Do tides also affect land?
Yes, though land rises and falls by a much smaller amount than the oceans.
Suppose you are in an elevator car when the elevator cable breaks. Which of the following correctly describes what happens and why.
You float weightlessly within the elevator car because you and the elevator both begin to accelerate downward at the same rate.
Suppose you are in an elevator car when the elevator cable breaks. Which of the following correctly describes what happens and why. You will crash you head into the elevator car ceiling because Earth's gravity will be pulling the car down faster than it pulls you down. You float weightlessly within the elevator car because you and the elevator both begin to accelerate downward at the same rate. You will remain stuck to the elevator floor as you and the elevator plunge downward toward a horrific crash. You will crash you head into the elevator car ceiling because the car will be falling rapidly away from you. You float weightlessly within the elevator car because Earth's gravity is no longer tugging on you.
You float weightlessly within the elevator car because you and the elevator both begin to accelerate downward at the same rate.
Study the graph of the intensity of light versus wavelength for continuous spectra, observing how it changes with the temperature of the light bulb. Recall that one of the laws of thermal radiation states that a higher-temperature object emits photons with higher average energy (Wien's law). This law is illustrated by the fact that for a higher temperature object, the graph peaks at __________.
a shorter wavelength
If you heat a rock until it glows, its spectrum will be:
a thermal radiation spectrum.
The absorption line spectrum shows what we see when we look at a hot light source (such as a star or light bulb) directly behind a cooler cloud of gas. Suppose instead that we are looking at the gas cloud but the light source is off to the side instead of directly behind it. In that case, the spectrum would __________.
be an emission line spectrum
If the Moon were closer to Earth, high tides would:
be higher than they are now.
You have found that tides on Earth are determined primarily by the position of the Moon, with the Sun playing only a secondary role. Why does the Moon play a greater role in causing tides than the Sun?
because the gravitational attraction between Earth and the Moon varies more across Earth than does the gravitational attraction between Earth and the Sun
The set of spectral lines that we see in a star's spectrum depends on the star's:
chemical composition.
Which lists the major steps of solar system formation in the correct order?
collapse, condensation, accretion
Leftover ice-rich planetesimals are called
comets.
Which of the following did not occur during the collapse of the solar nebula?
concentrating denser materials nearer the Sun
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 3 decreases by a factor of 3 decreases by a factor of 9 increases by a factor of 9
decreases by a factor of 9
Ionization is the process by which
electrons escape from atoms.
Planetary orbits are:
fairly circular and in the same plane.
Compared to red light, blue light has higher frequency,
higher energy, and shorter wavelength.
When a spinning ice skater pulls in his arms, he spins faster because _________. his angular momentum must be conserved, so reducing his radius must increase his speed of rotation there exists an unbalanced reaction force there is less friction with the ice there is less friction with the air
his angular momentum must be conserved, so reducing his radius must increase his speed of rotation
What is Jupiter's main ingredient?
hydrogen and helium
The solar nebula was 98 % ...
hydrogen and helium.
Where should you put a telescope designed for ultraviolet observations?
in Earth orbit
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 __________.
less than your normal weight at rest
In the illustration of the solar spectrum, the upper left portion of the spectrum shows the __________ visible light.
lowest frequency
What are the units for acceleration?
m/s^2
Compared to terrestrial planets, jovian planets are __________.
more massive and lower in average density
How many of our solar system's large moons orbit their planets in the same direction as their planet rotates?
most
If you wanted a radio telescope to achieve the same angular resolution as a visible-light telescope, it would need to be:
much larger.
Click "show" for the emission line spectrum, then click "choose gases" and study the emission line spectrum for neon. The neon "OPEN" sign appears reddish-orange because __________
neon atoms emit many more yellow and red photons than blue and violet photons
What substances existed as solid flakes within the innermost regions (within about the inner 0.3 AU) of the solar system before planets began to form?
none
The Cassini spacecraft:
orbited Saturn.
The nebular theory holds that
our solar system formed from the collapse of an interstellar cloud of gas and dust.
Now consider why the observed patterns of motion lead to the conclusion that the planets were not born in separate, random events. The reason for this conclusion is that, if the planets had been born in separate, random events, we would expect that __________.
planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane
A spectral line that appears at a wavelength of 321 nmnm in the laboratory appears at a wavelength of 328 nmnm in the spectrum of a distant object. We say that the object's spectrum is:
redshifted.
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
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
Notice that the Sun's spectrum appears brightest (or most intense) in the yellow-green region. This fact tells us __________.
the approximate temperature of the Sun's surface
When you are standing on a scale in an elevator, what exactly does the scale measure?
the force you exert on the scale
When 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
Observations show that interstellar clouds can have almost any shape and, if they are rotating at all, their rotation is not perceptible. However, the nebular theory predicts that a cloud will rotate rapidly once it shrinks to a relatively small size. What physical law explains why a collapsed cloud will rotate rapidly?
the law of conservation of angular momentum
The nebular theory also predicts that the cloud should heat up as it collapses. What physical law explains why it heats up?
the law of conservation of energy
Consider the hypothetical discovery from Part A reading: "Beyond its jovian planets, a star has two ice-rich objects as large as Mars." This discovery is consistent with the nebular theory, because this theory predicts that _________.
this might have happened in our own solar system if it had taken longer for the solar wind to clear the solar nebula
On average, Venus is the hottest planet in the solar system - even hotter than Mercury.
true
The mass of the Sun compared to the mass of all the planets combined is like the mass of an elephant compared to the mass of a cat.
true
The weather conditions on Mars today are much different than they were in the distant past.
true
Any particular location on Earth experiences __________.
two high tides and two low tides each day
Compared to an atom as a whole, an atomic nucleus is
very tiny but has most of the mass.