Astronomy Ch. 2 TEST: The Copernican Revolution

Which concept was NOT a part of Kepler's Laws of Planetary Motion?

Epicycles are needed to explain the varying brightnesses of the planets

What was a contribution to astronomy made by Copernicus?

He laid out the order and relative motion of the known solar system

What contribution to astronomy was made by Tycho Brahe?

His observations of planetary motion with great accuracy proved circular orbits could not work

The Law of Universal Gravitation was developed by...

Newton

A circlular orbit would have an eccentricity of...

0

geosynchronous satellites orbit at about four earth radii, where the earth's gravitational pull is...

1/16 g

How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it is on Saturn at 10 AU?

100x

Compared to the orbital velocity, escape velocity is about...

40% more

Kepler's second law implies what about planetary motion?

A planet moves faster when it is closer to the Sun.

The heliocentric model was actually first proposed by...

Aristarchus

The principle culture that transferred Greek astronomical knowledge to Renaissance Europe was...

Islamic

Explain Kepler's laws (essay)

Kepler's First Law: Planetary orbits are elipses, sun at one focus. The orbit of each planet around the sun is an ellipse Kepler's Second Law: A line joining a planet and the Sun sweeps out equal amounts of area in equal intervals of time. Planets move farther in each unit of time when they are closer to the Sun and vice versa Kepler's Third Law: Describes the relationship between how long it takes a planet to orbit a star and how far away that the planet is from the star. The closer the planet is to the star, the faster the orbit. For example: Earth takes one earth year to complete one orbit around the sun while Jupiter takes 30 years

A fatal flaw with Ptolemy's model is its inability to predict the observed phases of...

Mercury and Venus

What does Kepler's third law imply about planetary motion?

Planets further from the Sun orbit at a slower speed than planets closer to the Sun

The most accurate Greek attempt to explain planetary motion was the model of...

Ptolemy

A planet whose distance from the Sun is 3 A.U. would have an orbital period of how many Earth-years?

Square root of 27

The most famous prehistoric astronomical observatory is...

Stonehenge

Which of the statements below is part of both the Ptolemaic and Copernican models?

The Moon orbits the Earth once a month

Upon which point do Copernicus and Kepler disagree?

The orbits of the planets are ellipses, with one focus at the Sun

Combining Newton's and Kepler's laws, we can weigh the Sun, provided we know...

The size of the A.U. and the exact length of the year

Galileo found the rotation period of the Sun was approximately...

a month

Which of these was NOT a part of the original Copernican model? a. Mercury speeds up at perihelion, and slows down at aphelion b. Mercury must move faster in its orbit than any other planet c. Venus can go all the way around the Sun d. the Sun lies at the center of the solar systen e. Earth rotates rotates on its axis once a day

a. Mercury speeds up at perihelion, and slows down at aphelion.

Which of these was NOT seen telescopically by Galileo? a. Stellar parallax b. Four moons around Jupiter c. sunspots d. craters and mare on the moon e. venus' phase cycle

a. stellar parallax

Which of these observations of Galileo refuted Ptolemy's epicycles? a. the complete cycle of Venus' phases b. the craters on the Moon c. the rotation of sunspots across the Sun's surface d. the visibility of many more stars with the telescope e. the revolution of Jupiter's moons around it

a. the complete cycle of Venus' phases

According to Copernicus, the retrograde motion for Mars must occur

at opposition, when the earth overtakes Mars and passes between Mars and the Sun

On which of these assumptions do Ptolemy and Copernicus agree? a. the Sun was bigger than the Earth b. all orbits must be perfect circles c. Earth must be the center of all motion in the Cosmos d. Venus must always stay between us and the Sun e. the Sun must orbit us, but the planets do orbit the Sun

b. all orbits must be perfect circles

Which of the following was NOT a contribution of Galileo to astronomy? a. sunspots showed the Sun was rotating on its axis, like the Earth does b. the changing appearance of Saturn's rings corresponds to our seasons c. the phases of Venus prove it orbits completely around the sun d. the four moons of Jupiter are a model for the solar system motions in general e. the craters and mare of the Moon prove it a world in its own right

b. the changing appearance of Saturn's rings corresponds to our seasons

If the distance between two asteroids is doubled, the gravitational force they exert on each other will...

be one fourth as great

The Ptolmaic model probably persisted for all these reasons EXCEPT: a. it had the authority of Aristotle behind it b. it used perfect cirlces, which appealed to geometry c. it accounted well for Galileo's observation of the phase cycle of Venus d. it was consistent with the doctrines of the Catholic Church e. it explains why stellar parallax was not observed by the Greeks

c. it accounted well for Galileo's observations of the phase cycle of Venus

Which of these was NOT a telescopic discovery of Galileo? a. sunspots and the rotation of the Sun b. the four largest moons of Jupiter c. the moons of Saturn d. craters and mare on the Moon e. Venus' phase cycle

c. the moons of Saturn

According to Newton's Law of Universal Gravitation, if the Moon were three times further from Earth, the force by Earth on the Moon would...

decrease by a factor of 3

How does Newton's Universal Law of Gravitation explain Kepler's law? a. Universal gravitation implies that the orbits of the planets must be elliptical (Kepler's first law) b. Universal gravitation implies that the planets further from the Sun will move more slowly than the planets closer to the Sun (Kepler's third law) c. Universal gravitation implies that the planets will sweep out equal areas in equal times (Kepler's second law) d. Universal gravitation implies that when a planet is closer to the Sun in its orbit, it will move faster than when it is farther from the Sun (Kepler's second law) e. Both C and D are correct

e. Both C and D are correct

Which of the following is a contribution to astronomy made by Galileo? a. Jupiter has four moons orbiting it b. Venus appears almost fully lit when it lies on the far side of the Sun c. the Moon has craters, mountain, valleys, and dark flat areas on its surface d. the astronomical telescope can show us far more detail than the eye can e. all of the above

e. all of the above

Which of these was a contribution of Newton to astronomy? a. The Sun's gravity is greatest on a planet at perihelion, so the planet must speed up b. artificial satellites could be put into orbit about the Earth c. the Moon pulls as strongly on us as we do on it d. his differential calculus lets us calculate planetary motions more accurately e. all of these were due to Newton's work

e. all of these were due to Newton's work

The force of gravity varies with the a. inverse square of the distance separating the two bodies b. inverse of the two masses c. product of the two masses d. both A and B are correct e. both A and C are correct

e. both A and C are correct

Kepler's first law worked, where Copernicus' original heliocentric model failed, because Kepler described the orbits as...

elliptical, not circular

The Ptolemaic model of the universe...

explained and predicted the motions of the planets with deferents and epicycles

Tycho Brahe's contribution to Kepler's Laws of Planetary Motion were...

his detailed and accurate observations of the planet's position

The force of gravity between two objects...

increases with the masses of the bodies, but decreases with the square of the distances between them

According to Copernicus, retrograde motion for Venus must occur around

inferior conjunction, when it passes between us and the Sun

Escape velocity is the speed required to...

overcome the gravitational pull of an object

The place in a planet's orbit that is closest to the Sun is called

perihelion

According to Kepler's third law the square of the planet's period in years is...

proportional to the cube of its semimajor axis in A.U.

Today we rely on what technique to precisely measure distances in the solar system?

radar echo timings

Jupiter lies about 5 A.U. from the Sun, so at its distance...

the Sun's gravity is 25 times weaker than its pull on the Earth

The greatest contribution of the Greeks to modern thought was...

the development of scientific inquiry and model building

Orbital speed is the speed with which a planet moves around the Sun. This speed is determined by...

the mass of both the planet and the Sun and the distance between the two

Given that the planet orbiting the nearby star 51 Pegasi is about 20x larger than the Earth, but 400x more massive, on that world you would weigh...

the same as you do here

Scientists today do no accept the Ptolemaic model because...

the work of Tycho and Kepler showed the heliocentric model was more accurate

It took two centuries for the Copernican model to replace the Ptolemaic model because...

there was no scientific evidence to support either model until Galileo made his observations

During the eighteenth and nineteenth centuries, attempts to precisely measure the astronomical unit relied largely on rare...

tranists of the inferior planets across the Sun