Astronomy Quiz 2
1.Which has more mass: an armful of feathers or an armful of lead? 2.Which has more volume: a kilogram of feathers or a kilogram of lead? 3.Which has higher density: a kilogram of feathers or a kilogram of lead?
1. lead 2. feathers 3. lead
The Earth was identified as a sphere during the time of classical Greece, yet claims that the Earth is flat have recently regained some traction among celebrities and the public. What of the following are evidence from astronomy that the Earth is spherical and not flat? 1.The Moon's terminator is rounded. 2.Jupiter has several moons that orbit it. 3.Other planets have periodic retrograde motion in the sky. 4.The sun reaches a higher point in the sky for observers closer to the equator. 5.The shadow of the Earth on the Moon during an eclipse is rounded. 6.Parallax is observed for some distant stars. 7.Stars may appear higher in the sky for different observers depending on how far north or south the observers are.
7.Stars may appear higher in the sky for different observers depending on how far north or south they are. 4.The sun reaches a higher point in the sky for observers closer to the equator. 5.The shadow of the Earth on the Moon during an eclipse is rounded. 1.The Moon's terminator is rounded.
When astronomers discuss the apertures of their telescopes, they say bigger is better. Explain why.
A. A bigger aperture allows you to use more magnification, produces image with higher resolution. Also collects light making for a sharper image and can detect fainter sources than a smaller one
25. What is the difference between the north pole of the Earth and the north celestial pole? A. Nothing, the north celestial pole is the north pole of the earth projected onto the sky. B. The north celestial pole is tilted by 231/2degrees with respect to the north pole of Earth. C. The north celestial pole lies in northern Canada. D. The north celestial pole is warmer than the north pole of Earth so Santa won't live there. E. none of the above
A. Nothing, the north celestial pole is the north pole of the earth projected onto the sky.
What is meant by "reflecting" and "refracting" telescopes?
A. Reflecting Telescopes use a mirror rather than a lens to form an image B. Refracting Telescopes a long tube with a large glass lens at one end, uses a lens as its main optical element to form an image
34. If the history of the universe was compressed into a year, when in that year did the first stars and galaxies form? A. Sometime in early January B. December 31 C. Sometime in June D. Mid-December E. none of the above
A. Sometime in early January
What are the three basic components of a modern astronomical instrument? Describe each in one to two sentences.
A. Telescope (mirror/lens) , For collecting visible light. B. An Instrument, Sorts the incoming radiation by wavelength. C. Detector, a device that senses the radiation in the wavelength regions selected. Then it records the observations.
3. The Moon's rotation is synchronous, which means its rotation period is the same as its orbital period around the Earth. As a consequence,. A. The Moon always keeps the same face turned toward Earth. B. The Moon has a small magnetic field. C. The tides interact between the Earth and Moon. D. The Moon and Earth were formed at about the same time. E. none of the above
A. The Moon always keeps the same face turned toward Earth. There is a tidal bulge on the Moon, just as there is on the Earth. On the Earth, this bulge is just a little bit ahead of where it would otherwise be because of the spin of the Earth. In the previous question, we said that the bulge causes the Moon to try to race ahead a little bit. Newton's first law tells us that if the Moon is getting pulled ahead, the bulge must be getting pulled back. This results in some friction that slows down the rate of spin of the Earth.When the Moon was just formed it spun (and orbited) much faster that it does today. The tidal friction of the Earth slowed down the Moon faster than the Moon slowed the Earth. This led to the Moon spinning at the same rate that it orbits, so that the same side faces the Earth at all times.
7. The Moon doesn't continue moving in a straight line. What did Newton conclude from this? A. The moon is being acted on by a force (gravity). B. That gravitational mass and inertial mass must be the same. C. The moon only appears to be moving because we are moving around it. D. both B and A E. none of the above
A. The moon is being acted on by a force (gravity). Newtons first law tells us that there must be an outside force acting on the Moon to continually change its direction and keep the Moon in orbit. If there were no force acting on the Moon, it would continue moving in a straight line at constant velocity.Newton thought it a coincidence that gravitational mass and inertial mass are the same, but did not explore that concept any further. The Moon is moving around the Earth, not the other way round.
Name the two spectral windows through which electromagnetic radiation easily reaches the surface of Earth and describe the largest-aperture telescope currently in use for each window.
A. Visible Light, Radio Waves B. Radio - 305-m , at Arecibo, Puerto Rico ; Visible Light - 10.4m Mirror, Canary Island
15. What Solar System objects are best described as "dirty snowballs?" A. comets B. planets C. asteroids D. satellites E. none of the above
A. comets Comets are icy bodies in space that release gas or dust. They are often compared to dirty snowballs. Asteroids and satellites are typically rocky, planets are either rocky balls or large spheres of gas.
19. Technically, next year the Moon will be A. farther from the Earth B. rotating much faster C. rotating much slower D. closer to the Earth E. none of the above
A. farther from the Earth The moon is slowly migrating away from the Earth. This is caused by the effects of tides on the Earth. The gravity of the Moon causes a tidal bulge on the Earth, most noticeable in the oceans, although there is also a tide on land. If the Earth weren't spinning, the bulge would be on the side of the Earth nearest the Moon and the side furthest from the Moon. Earth's spin causes the bulge to move a little bit ahead of where it would normally be. The Moon feels a slightly stronger gravitational pull toward the bulge, making the Moon try to catch up to it. In turn, this makes the Moon move a little bit faster than it would in its orbit, which results in the Moon moving away from the Earth.
12. On a full Moon, the Moon will rise at A. sunset B. sunrise C. midnight D. midday E. none of the above
A. sunset At full Moon, the moon rises at sunset and sets at sunrise. At 3rd quarter, the moon rises at midnight and sets at noon. At new, the moon rises at sunrise and sets at sunset, and we don't see any of the illuminated side! The Moon is exactly 180◦away from the Sun when it is full. On the equinox, the Moon rises just as the Sun sets, typically about 6 p.m, and the Moon sets when the Sun rises, 6a.m. in this example. That means that the Moon is visible between 6 p.m. and 6 a.m. when it is full on an equinox. During other times of year the full Moon may rise a little before sunset (winter) or a little after sunset (summer). In any case, the Moon is visible overnight at all of the times listed.
1. When you are in space, far from anything that could exert a gravitational influence, you no longer have A. weight B. magnetic fields C. electric charge D. mass E. none of the above
A. weight Mass the fundamental source of inertia as well as gravity for a body. An electric charge is determined by the relative numbers of protons and electrons, most objects have a net neutral or very, very small electric charge. Magnetic fields are related to electrical currents; your body as a whole typically has no magnetic field, though individual atoms and molecules may have weak magnetic fields.Weight is the gravitational force upon a mass. When far from any gravitational influence, you would experience no gravitational force and thus have no weight.
24. After THREE half-lives, what fraction of the original number of radioactively decaying atoms remains? A.1/8 B.1/6 C.1/4 D.1/2 E. none of the above
A.1/8 Each half-life reduces the remaining fraction by one half. If initially have 1 unit of some radioactive substance, after one half-life,1/2will remain. After a second half-life, (1/2×1/2=1/4) will remain. After the third half life,1/2×1/4=1/8remains.
22. According to the law of universal gravitation, what would happen to Earth if the Sun were some how replaced by a black hole of the same mass? A. Earth would be quickly sucked into the black hole. B. Earth's orbit would not change. C. Earth's orbit would be twice as far from the black hole. D. Earth would slowly spiral in to the black hole. E. none of the above
B. Earth's orbit would not change. Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. If the Sun were replaced by a blackhole of the same mass, the distance and the mass will remain the same. So, the Earths orbit would not change.
30. Who first organized the observations of the objects in the solar system into simple, mathematical relationships? A. Galileo B. Kepler C. Tycho D. Newton E. Holst
B. Kepler Tycho Brahe preceded everyone else on this list. He made very detailed observations of the positions of stars and the planets. Tycho had his own model of the Universe that was largely based on the Copernican model but did not try to explain the system or the details of planetary motion using simple mathematics. Galileo and Kepler were contemporaries, though Galileo was focused primarily on the observational evidence of the Copernican model and discovering what could be seen with a telescope.Kepler was a student of Tycho who used Tycho's detailed tables to figure out the motion of the planets around the Sun. (As a side note, Tycho died unexpectedly while Kepler was working with him. It has been speculated that he was poisoned with mercury, perhaps by Kepler in order to have unfettered access to Tycho's data, which Tycho was extremely protective of). Kepler established the first simple mathematical laws that describe the motion of the planets.Newton came along a generation after Galileo and Kepler. He was the first to describe forces and gravity with relatively simple mathematics, and provided a theoretical underpinning for Kepler's laws.Holst is a early 20th century composer best known forThe Planets.
20. This year's summer solstice in Austin will occur on June 21st. In what direction will the Sun rise over the horizon on that day? A. Due North B. North of East C. Due East D. South of East E. Due South
B. North of East
2. According to Newton's first law, if an object is moving, it will keep moving forever. However, if we push an eraser on the table, it will eventually stop. Why? A. because of gravity B. because there is a force acting on the eraser C. because there are no forces pushing the eraser forward D. because of Newton's Inverse Square Law E. because Newton's first law is wrong.
B. because there is a force acting on the eraser Newton's first law states that every object will remain at rest or move at constant velocity in a straight line unless compelled to change its state by the action of an external force. In this question, theres an external force: friction, applied to the eraser by the table.
27. Kepler's "equal area, equal time" law implies that A. planets move slowest when they are closest to the Sun B. planets move fastest when they are closest to the Sun C. planets move in ellipses D. the ratio of the cube of the semi-major axis to the square of the period is a constant E. none of the above
B. planets move fastest when they are closest to the Sun Kepler's second law says that a planet 'sweeps out' an equal area in an equal time. Imagine theSun and a planet in a room, with a string between them and brooms hanging down from the string. As the planet moves around the Sun in its orbit, the brooms would sweep part of the floor. As long as you measure the orbit over the same period of time, the same amount of floor will be swept up. If the orbit is a circle, this is true in an obvious way, e.g. as the planet moves a quarter way around the circle, a quarter of the area is swept - it doesn't matter what part of the circle you start in. If the orbit is a really elongated ellipse, the Sun will be at one focus of the ellipse; when the planet is furthest away from the Sun there is a long line of brooms that is sweeping the floor, but when the planet is closest to the Sun there is only a short line of brooms that is sweeping. That means that to sweep and equal area in an equal time, the planet needs to move faster when it is closest to the Sun, or slower when it is further away. The relation between the semi-major axis and the period is Kepler's third law, which is dependent upon the details of gravity. While the second law must be true if the third law is true, the corollary is not necessarily true — the third law does not have to be true for the second law to be true, though our universe would look very different if that were the case.
11. Which of the following did Newton NOT predict or describe? A. the force of gravity between planets B. the cause of gravity C. the difference between mass and weight D. the physics of motion E. elliptical orbits for planets
B. the cause of gravity Newton's laws explicitly describe the physics of motion and the force of gravity between planets, and identified the difference between mass and weight in the process. Elliptical orbits are a natural consequence of Newton's laws. Newton made no attempt, however, to explain the cause of gravity.
33. You may be familiar with your astrological sign based on a system established in ancient times; however, if you record the position of the Sun along the zodiac on your birthday, you will find it to lie within a different constellation. What can explain this discrepancy? A. the invention of leap years B. the precession (wobble) of the Earth's rotation axis C. the decline in believers of pseudoscience D. the speeding up of the Earth's rotation E. none of the above; the Sun is always in the same constellation
B. the precession (wobble) of the Earth's rotation axis
Why was Brahe reluctant to provide Kepler with all his data at one time?
Brahe didn't want kepler to figure out more discoveries and become more famous
After four half-lives, what fraction of the original number of radioactively decaying atoms remains? A. 1/4 B. 4/2 C. 1/16 D. 50%
C. 1/16 After each half-life, 50% of the existing material has decayed. After the first half-life there is 50% (1/2 ) or the original material left So 1/16 is the correct answer.
9. The largest terrestrial planet and giant planet are, respectively: A. Earth and Saturn. B. Venus and Jupiter. C. Earth and Jupiter. D. Venus and Saturn E. none of the above
C. Earth and Jupiter. In our solar system, there are four terrestrial planets, which also happen to be the four closest to the Sun: Mercury, Venus, Earth, and Mars. Of the four terrestrial planets, Earth is the largest. Jupiter,Saturn, Uranus and Neptune are gas giants, also known as Jovian planets, of our solar system. Jupiter is the largest of these.
16. In what limit does Newtonian gravity stop being a good approximation? A. For Apples falling toward Earth (laptop kind) B. For pieces of paper falling toward Earth. C. In the limit where gravity is very strong, e.g. Mercury's orbit D. For apples falling toward Earth (edible kind) E. None of the above
C. In the limit where gravity is very strong, e.g. Mercury's orbit Newton's laws are a mathematical model that is limited to non-relativistic speeds and weak gravitational fields. Within those limits it is exceedingly accurate. In principle, both the Earth's orbit and that of Mercury are affected by the sun's gravitational field in a non-Newtonian manner. But, because the Earth is so far out, the effect is negligible. There is a much larger effect near Mercury, being much closer to the Sun, which is large enough to be observed.
The acceleration due to gravity on earth is about 10 m / s^2 (meaning if you fall for 1 second, you will be moving at 10 m/s, if you fall for 2 seconds, you will be moving at about 10 m/s + 10 m/s = 20 m/s). The International Space Station is orbiting Earth at about 400 km (250 mi) above the surface of the planet. Astronauts and the space station are often described as weightless. From Newton's law of gravity, what is the difference between the gravity that the astronauts experience here on Earth versus that they experience while in orbit? A. The astronauts experience no gravity at all. B. The astronauts experience significantly weaker gravity (less than half) when in orbit. C. The astronauts experience about the same gravity when in orbit (perhaps only a small increase or decrease from on Earth). D. The astronauts experience significantly stronger gravity (more than half) when in orbit.
C. The astronauts experience about the same gravity when in orbit (perhaps only a small increase or decrease from on Earth).
32. The apparent retrograde motion of the path of Mars is a consequence of which of Kepler's Laws? A. First Law: orbits are ellipses B. Second Law: equal area in equal time C. Third Law: planets farther away from the Sun move more slowly D. none of the above E. all of the above
C. Third Law: planets farther away from the Sun move more slowly Retrograde motions of Mars is due to Mars moving more slowly in its orbit than is the Earth inits orbit. When the Earth is relatively far away from Mars we can see Mars moving 'forward', but as we catch up and pass Mars, we briefly see it moving 'backward' relative to the distant stars. Kepler's third law tells us that the further away a planet is from the Sun, the longer it takes for that planet togo around the Sun. The exact ratio that Kepler determined between the period and distance requires that the planet must be moving more slowly if it is further away from the Sun. The observed retrograde motion of Mars is a demonstration of this effect.
21. A lunar eclipse is visible A. To only some portions on the night side of the Earth when the eclipse occurs. B. To everyone on Earth when the eclipse occurs. C. To everyone on the night side of the Earth when the eclipse occurs. D. To only some portions on the day side of the Earth when the eclipse occurs. E. none of the above
C. To everyone on the night side of the Earth when the eclipse occurs.
4. Which of the following statements is NOT one of Newton's Laws of Motion? A. The rate of change of momentum of an object is equal to the net force applied to the object. B. In the absence of a net force acting upon it, an object moves with constant velocity. C. What goes up must come down. D. For any force, there always is an equal and opposite reaction force.
C. What goes up must come down. Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change by the action of an external force. This is normally taken as the definition of inertia. The key point here is that if there is no net force acting on an object or if all the external forces cancel each other out then the object will maintain a constant velocity. If that velocity is zero, then the object remains at rest. If an external force is applied, the velocity will change because of the force. The second law explains how the velocity of an object changes when it is subjected to an external force.The law defines a force to be equal to change in momentum (mass times velocity) per change in time.The third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal force on object A.For choice C, if theres no net force applied on an object which is going up, the object will keep going up at a constant velocity based on Newtons first law of motion.
25. Imagine a scale model where the Earth is a dot on the end of your nose and the Sun is the size of anorange and is located at your desk. About how big and about how far away would the next star nearest the Sun be? A. a basketball in Gregory Gym B. an orange at the back of the classroom C. an orange in Chicago D. an orange in Round Rock
C. an orange in Chicago Most stars are more or less the same size (well get into more details about the size of stars later in the semester), so the next nearest star to our own Sun would also be the size of an orange in this analogy. The nearest star is about 4 light years (23 trillion miles) away; the Sun is about 1 million miles in diameter, meaning that the nearest star is about 27 million times the Suns diameter away. For the Sun to be an orange, you would have to line up about 27 million oranges between the Sun and its neighbor. At about 2 inches each, that is 54 million inches = 4.5 million feet = 850 miles, which takes you roughly to Chicago.
8. According to Newton's second law, if I apply the same force to objects with different masses, the one with twice the acceleration will have the mass. A. twice B. four times C. half D. one fourth E. none of the above
C. half Assume the same force F is applied to two objects: m1 and m2. According to Newtons second law:F=m1a1=m2a2. When a1= 2a2,F=m1a1= 2m1a2=m2a2. This results in m1=m2/2.
6. The characteristic rotation of large storms on the Earth is the result of A. the Earth's magnetic field axis not being aligned perfectly with the Earth's rotation B. the Earth's active asthenosphere C. the Coriolis effect (rotational velocities are faster at the equator than at the poles) D. both A and B E. both A and C
C. the Coriolis effect (rotational velocities are faster at the equator than at the poles) The apparent force that deflect the storms is called the Coriolis force. It is an apparent force that occurs on objects that are moving in a spinning reference frame, like the Earth. As the Earth spins on its axis from west to east, an object in the northern hemisphere that moves directly north will appear to move a little bit east as the Earth moves beneath it, or an object moving south will move a little bit west. This effect is reversed in the southern hemisphere. Air and water are generally note magnetic, so the magnetic field of the Earth has no effect on storms.The asthenosphere is inside the Earth, so it also has no effect on storms.
14. It has been billions of years since the Earth formed, yet it still has an active, circulating asthenosphere.What is the most important source of the heating that drives this activity? A. nuclear fusion of light elements into heavier elements like hydrogen to helium B. greenhouse gasses like carbon dioxide (CO2) hindering the escape of infrared radiation. C. the radioactive decay of heavy elements like uranium-238 and thorium-232. D. dark energy and dark matter E. none of the above
C. the radioactive decay of heavy elements like uranium-238 and thorium-232. Dark energy probably does not interact with normal matter at all; dark matter interacts only via gravity, and therefore isn't a major source of heating. Nuclear fusion requires very high temperatures, such as those found in the center of the Sun. Greenhouse gasses help retain solar heat in the atmosphere, but only keep the planet about 40 degrees Celcius warmer than the planet would otherwise be and largely only affect the temperature of the atmosphere, oceans, and first few meters of the land surface.Radioactive decay of long lived elements such as U-238 provide large quantities of energy deep within the Earth that keep the temperature of the interior of the planet very warm.
29. Kepler's laws are called empirical laws because A. the emperor in Kepler's time decreed them to be true B. they revolutionized our understanding of the world in a profound way C. they explain a set of observed phenomena without providing any underlying theoretical explanation for why the world seems to work that way D. they are based solely on a theoretical understanding of the world E. they provided a framework for Newton, possibly the greatest scientist of all time, to devise even better laws
C. they explain a set of observed phenomena without providing any underlying theoretical explanation for why the world seems to work that way "Empirical" here refers to explaining observations without understanding the underlying causes of the observations. To give another example, bread, cheese, beer, wine, and spirit making were all empirical professions until the advent of germ theory in the 19th century — the cause of fermentation was not known, but the methods needed to produce these products was understood for thousands of years prior to the discovery of the yeast and bacteria that are responsible for converting the sugars and proteins in the milk, flour, grains, and fruits that are necessary to make the final product.
Carbon-14 is a radioactive form of carbon with a half-life of about 6000 years. It is useful for dating fossils and bones of living organisms. Suppose you find a set of bones that you wish you find the age of. You analyze the carbon in the bones and find that only 1/4 of the original carbon-14 remains. How old are the bones? A. 1500 years old. B. 24000 years old. C. There is no way to tell from the information given. D. 12000 years old.
D. 12000 years old.
26. What evidence did Galileo use to justify adoption of the Copernican model of the solar system? A. he observed objects orbiting something other than Earth B. he discovered that Venus went through phases similar to our Moon C. he discovered craters on the Moon D. A and B E. all of the above
D. A and B Galileo was the first to observe (that we know of) the Moons of Jupiter and see them "disappear"as they moved into the shadow of the giant planet (unlike our Moon, Jupiter's Moons experience a lunar eclipse every "month"). He deduced this as evidence that Jupiter's Moons were in orbit about Jupiter, just as the Earth and other planets were in orbit about the Sun.Galileo's observations of Venus revealed that it goes through phases from new to full like our own Moon.This effect is predicted even in the Ptolemaic model of the universe, but the durations of and times in which the phases occur differ from those in the Copernican model. Galileo confirmed that the phases occurred as predicted by the Copernican model.Galileo, through his training in art (who says scientists don't need to know art!), was the first to identify the features seen on the surface of the Moon as mountains and valleys through the shadows that they create. However, this detail doesn't provide evidence for or against the other planets orbiting the Sun or the Earth.
23. Which of the following process cause the greenhouse effect A. Visible sunlight penetrates atmosphere and is absorbed by the ground. B. Thermal infrared wavelengths are strongly absorbed by greenhouse gases, heating the atmosphere C. The energy is re-emitted as infrared or heat radiation. D. All of the above E. None of the above
D. All of the above To begin with, visible sunlight penetrates the atmosphere and is absorbed or reflected by the ground. The energy absorbed by the ground is re-emitted as heat (infrared) radiation. Infrared wave-lengths are strongly absorbed by greenhouse gases such as CO2, methane, and ozone, so instead of escaping into space the infrared radiation is absorbed by the atmosphere, making it hotter. This whole process caused the greenhouse effect.
10. A week after NEW moon, the Moon's phase is: A. Waxing gibbous B. Waning crescent C. Third quarter D. First quarter E. Full
D. First quarter Waning crescent is after new moon but before the first quarter. First quarter moon is a week after the new moon. Full moon is two weeks after the new moon and third quarter is three weeks after the new moon. Waxing gibbous is between full moon (second week) and the third quarter (third week).
21. The terrestrial planets are A. mostly solid B. less massive than the gas giants C. found in the inner part of the solar system D. all of the above E. none of the above
D. all of the above A terrestrial, or rocky, planet is a planet that is composed primarily of silicate rocks or metals and have a solid planetary surface. Within the Solar System, the inner planets closest to the Sun are terrestrial planets.
31. Kepler's third law (the cube of the semi-major axis is proportional to the square of the orbital period)applies to A. all the terrestrial planets B. all the outer (gas) planets C. all the asteroids D. all of the above E. none of the above
D. all of the above Kepler's third law is a result of the gravitational pull between the Earth and Sun. The law of gravity applies to everything in the universe, so Kepler's third law holds true for any system in which one body is orbiting another due to gravity.
20. Two astronauts float near each other in open space. Since they both have mass, Newton's laws tell us that: A. they are each providing an acceleration, albeit negligible, to the other B. there is a gravitational force, albeit negligible, between them both C. they are completely isolated from each other D. both B and A E. none of the above
D. both B and A Gravity is well approximated by Newton's law of universal gravitation, which describes gravity asa force that causes any two bodies to be attracted to each other. The force is proportional to the product of their masses and inversely proportional to the square of the distance between them. Therefore, there is a gravitational force between two astronauts. Since there is a force experienced by the astronauts, there will be acceleration between them (F=ma). However, the astronauts are not isolated from each other.
17. Considering the Earth from the standpoint of comparative planetology, we would reason that the present lack of a magnetic field on the Moon is likely due to the Moon's A. frequent asteroid impacts B. rocky surface C. circulating, molten asthenosphere D. static asthenosphere E. predominantly radioactive core
D. static asthenosphere The asthenosphere is part of the upper mantle of the Earth that is highly viscous, mechanically weak and ductility deforming. Due to the temperature and pressure conditions in the asthenosphere, rock becomes ductile and flows. Since these rocks are rich in iron, the flow generates electric currents which in turn produce magnetic fields. The asthenosphere in the Moon is static, thus cannot generate magnetic fields.The Moon doesn't experience asteroid impacts any more frequently than the Earth. Those impacts have no effect on the magnetic field of either body.Radioactive decay help to heat both the interior of the Moon and the Earth; the Moon, being much smaller, radiates this heat more quickly, which allowed most of the interior of the Moon to solidify.
Newton's third law is commonly stated as "for every action there is an equal and opposite reaction". Let us again consider the International Space Station (ISS): what does Newton's third law mean for it? A.The ISS does not experience a force (action) in space, so there is no reaction. B.The ISS experiences the force of gravity, but Newton's third law doesn't apply in space. C.The ISS experiences a force (action) of gravity, and the opposite force (reaction) is applied to the astronauts aboard. D.The ISS experiences a force (action) of gravity, and the opposite force (reaction) is applied to the Earth.
D.The ISS experiences a force (action) of gravity, and the opposite force (reaction) is applied to the Earth.
What is the phase of the Moon during a total solar eclipse? During a total lunar eclipse?
During a solar eclipse, the Moon is new and during a lunar eclipse the Moon is full.
What are the two ways that the tilt of Earth's axis causes the summers in the United States to be warmer than the winters?
During our summer, the northern hemisphere is tilted towards the Sun. This causes the Sun to appear higher in the sky and the angle of incidence of the sunlight is nearer a right angle. This makes the intensity of the sunlight greater. In addition, since the Sun appears higher in the sky, it is above the horizon longer and therefore heats things up more than in the winter when days are shorter.
18. Roughly how many times could the Earth fit into the Sun (by volume)? A. 1 B. 10 C. 100 D. 1,000 E. 1,000,000
E. 1,000,000 The diameter (radius) of the Sun is about one hundred (102) times the diameter (radius) ofEarth. Since the volume of a sphere is:4/3πR3. The volume of the Sun is (102)3= 106times that ofEarth.
5. Significant tidal effects on the Earth are caused by A. the Moon B. the Sun C. Jupiter D. Mars E. A and B
E. A and B The Moon is a major influence on the Earths tides, but the Sun also generates considerable tidal forces. Solar tides are about half as large as lunar tides and are typically expressed as a variation of lunar tidal patterns, rather than as a separate set of tides. When the Sun, Moon, and Earth are in alignment (at the time of the new or full moon), the solar tide has an additive effect on the lunar tide, creating extra-high high tides, and very low, low tides — both commonly called spring tides. One week later, when the Earth, Moon, and Sun form a right triangle, the solar tide partially cancels out the lunar tide and produces moderate tides known as neap tides.
13. Kepler's third law (the cube of the semi-major axis is proportional to the square of the orbital period)applies to A. all the outer (giant) planets B. all the asteroids C. all the comets D. all the terrestrial planets E. all of the above
E. all of the above Kepler's third law provides an accurate relation between the period and distance for any object's orbit about the Sun.
28. Why was Copernicus' heliocentric model less accurate at predicting the positions of planets than Ptolemy's "spheres within spheres within spheres..." geocentric model? A. Ptolemy's model was more physically correct B. Ptolemy's model can always be improved by adding more "spheres within spheres" C. Copernicus didn't take into account parallax effects D. Copernicus modeled the planetary orbits as circles E. both B and D
E. both B and D Copernicus' model was more accurate ("physically correct") than was Ptolemy's as Ptolemy's model showed everything orbiting around the Earth and nothing orbiting the Sun. However, Ptolemy's model, by adding more and more spheres, could better account for the observed motions of the planets because Copernicus assumed that the planets must lie on perfect circles (related to the perfect spheres used in Ptolemy's model).Parallax is the apparent motion of distant stars due to Earth's motion around the Sun. Copernicus' model predicted parallax, though the model was discounted in part because parallax had never been observed — it wasn't until 1838, about 300 years after Copernicus died, that parallax of a star was first observed by Friedrich Bessel.
According to Kepler's second law, where in a planet's orbit would it be moving fastest? Where would it be moving slowest?
Fastest: when it's closest to the sun Slowest: when it's farthest from the sun
The gas pedal, the brakes, and the steering wheel all have the ability to accelerate a car—how?
Gas pedal - increase speed Brake - decrease speed Steering wheel - drives direction and acceleration of speed
What fraction of the Moon's visible face is illuminated during first quarter phase? Why is this phase called first quarter?
HALF
Why is Tycho Brahe often called "the greatest naked-eye astronomer" of all time?
He made many discoveries without a telescope.
State Kepler's three laws in your own words.
Kepler's first law: Each planet moves around the Sun in an orbit that is an ellipse, with the Sun at one focus of the ellipse. Kepler's second law: The straight line joining a planet and the Sun sweeps out equal areas in space in equal intervals of time. Kepler's third law: The square of a planet's orbital period is directly proportional to the cube of the semi major axis of its orbit. Kepler's three laws provide a precise geometric description of planetary motion within the framework of the Copernican system. With these tools, it was possible to calculate planetary positions with greatly improved precision. Still, Kepler's laws are purely descriptive: they do not help us understand what forces of nature constrain the planets to follow this particular set of rules. That step was left to Isaac Newton.
To calculate the momentum of an object, which properties of an object do you need to know?
Mass and velocity
Which of these properties of an object best quantifies its inertia: velocity, acceleration, volume, mass, or temperature?
Mass best quantifies inertia
Why do we say that Neptune was the first planet to be discovered through the use of mathematics?
Neptune was the first planet to be discovered by using mathematics. After the discovery of Uranus in 1781, astronomers noticed that the planet was being pulled slightly out of its normal orbit. John Couch Adams of Britain and Urbain Jean Joseph Leverrier of France, used mathematics to predict that the gravity from another planet beyond Uranus was affecting the orbit of Uranus. They figured out not only where the planet was, but also how much mass it had. A young astronomer, Johann Gottfried Galle, decided to search for the predicted planet and observed Neptune for the first time in 1846.
What was the great insight Newton had regarding Earth's gravity that allowed him to develop the universal law of gravitation?
Newton suspected that earths gravity is what kept the moon from hitting the earth
Write out Newton's three laws of motion in terms of what happens with the momentum of objects.
Newton's first law: Every object will continue to be in a state of rest or move at a constant speed in a straight line unless it is compelled to change by an outside force. Newton's second law: The change of motion of a body is proportional to and in the direction of the force acting on it. Newton's third law: For every action there is an equal and opposite reaction (or: the mutual actions of two bodies upon each other are always equal and act in opposite directions).
Pluto's orbit is more eccentric than any of the major planets. What does that mean?
Orbit is more elongated
Rank the following objects from smallest to largest. Halley's Comet The Moon Jupiter The Earth The Sun Neptune Titan
The correct order is: Halley's Comet The Moon Titan The Earth Neptune Jupiter The Sun
Why don't lunar eclipses happen during every full moon?
Tilt of Moons rotational axis around the Earth
Why did Kepler need Tycho Brahe's data to formulate his laws?
Tycho Brahe's accurate observations of planetary positions provided the data used by Johannes Kepler to derive his three fundamental laws of planetary motion.
Explain how a rocket can propel itself using Newton's third law.
When a rocket pushes against the earth the earth also pushes the object away at the same time.
