physics Homework

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 1/9

Homework 2 Due: 11:59pm on Friday, February 1, 2019

You will receive no credit for items you complete after the assignment is due. Grading Policy

Jupiter in Motion

Jupiter orbits the Sun at an average distance of 5.203 AU.

Part A - What is the length of its year in Earth years? Answer to two decimal places.

You did not open hints for this part.

ANSWER:

Motion of Mars

Mars's orbit is rather eccentric.

Part A - Does Mars move at a higher speed when it is farther away from the Sun or closer to it? Explain.

You did not open hints for this part.

ANSWER:

Kepler's 3rd Law

Part A - All of the following statements are true. Which one can be explained by Kepler’s third law?

You did not open hints for this part.

ANSWER:

Tycho Brahe

Part A - The great contribution of Tycho Brahe was to

ANSWER:

3785 Character(s) remaining

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Mars moves faster in its orbit when it is closer to the Sun than when it is farther from the Sun.

All the planets orbit the Sun in nearly the same plane.

Earth is slightly closer to the Sun in January than in July.

Venus orbits the Sun at a faster orbital speed than Earth.

The Sun is not in the precise center of Saturn’s orbit.

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 2/9

The Greeks

Part A - The ancient Greeks get a lot of attention for their contributions to science because

ANSWER:

Ellipses

Part A - Which of the following statements about an ellipse is NOT true?

ANSWER:

Eccentricities

Part A - When we say that a planet has a highly eccentric orbit, we mean that:

ANSWER:

Eris

possess a metal nose

discover four moons orbiting Jupiter, thereby lending strong support to the idea that Earth is not the center of the universe

offer the first detailed model of a Sun-centered solar system, thereby beginning the process of overturning the Earth-centered model of the Greeks

observe planetary positions with sufficient accuracy so that Kepler could later use the data to discover the laws of planetary motion

discover that planets orbit the Sun in elliptical orbits with varying speed

they were the first people to realize that Earth is a planet orbiting the Sun

they were the only ancient culture that kept written records of their astronomical observations

they were the first people known to try to explain nature with models based on reason and mathematics, without resort to the supernatural

the books of every other culture were lost in the destruction of the library of Alexandria

The semimajor axis of an ellipse is half the length of the longest line that you can draw across an ellipse.

The focus of an ellipse is always located precisely at the center of the ellipse.

An ellipse with a large eccentricity looks much more elongated (stretched out) than an ellipse with a small eccentricity.

A circle is considered to be a special type of ellipse.

it is spiraling in toward the Sun.

in some parts of its orbit it is much closer to the Sun than in other parts.

it has an odd but strangely endearing personality

its orbit is an ellipse with the Sun at one focus.

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 3/9

The recently discovered Kuiper Belt object Eris orbits the Sun every 557 years.

Part A - What is its average distance (semimajor axis) from the Sun in AU? Answer to one decimal place.

You did not open hints for this part.

ANSWER:

Tychonic Models

Part A - Which of the following is NOT true of Tychonic models of the universe?

ANSWER:

Perfecto!

Part A - Rank the following shapes in from most (left) to least perfect (right) according to the ancient Greeks.

You did not open hints for this part.

ANSWER:

The Moon orbits the Earth.

They gained widespread acceptance in Tycho's time.

The Earth orbits the Sun.

The planets orbit the Sun.

The Sun orbits the Earth.

Reset Help

The correct ranking cannot be determined.

Circle Hexagon Square Decagon Octagon

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 4/9

Homocentric Models

Part A - Why does the homocentric model of Eudoxus have so many spheres? Explain how these spheres are attached to each other.

ANSWER:

Aristotle's Model

Part A - Select all of the following which are NOT true of Aristotle's model of the universe.

ANSWER:

Ptolemy vs. Copernicus

Part A - Describe the advantages of the model of Copernicus over that of Ptolemy. What are Copernicus's lasting achievements?

ANSWER:

Greeks & Planetary Motion

Part A - Why did the ancient Greeks reject the real reason for planetary motion?

ANSWER:

3785 Character(s) remaining

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The universe is divided into the celestial and sublunar worlds.

The celestial world is made of the elements of Earth, Wind, Fire, and Water.

The motion of all of the celestial spheres is derived from the Prime Mover.

The model fit Babylonian data quite well.

There are 56 celestial spheres.

The Prime Mover, the inner-most sphere, drives the motion of all the other spheres.

3785 Character(s) remaining

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1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 5/9

Constellations

Part A - What do astronomers mean by a constellation?

ANSWER:

The Ecliptic

Part A - What is the ecliptic?

ANSWER:

Angular Size

Part A - Which of the following statements does NOT use the term angular size or  angular distance correctly?

ANSWER:

Mooned

They were too busy screaming This is Sparta!!! to research the real reason.

It is incompatible with a flat Earth.

The Sun really does revolve around the Earth. 

The apparent rotation of the celestial sphere about the Earth fooled them.

The stars are too far away for stellar parallax to be observable with the naked eye.

They did not believe that the gods would design the universe that way.

A constellation is a group of stars related through an ancient story.

A constellation is any random grouping of stars in the sky.

A constellation is a region in the sky as seen from Earth.

A constellation is a group of stars that are all located in about the same place in space.

the Sun's daily path from east to west in our sky

the path the Sun appears to trace around the celestial sphere each year

a half-circle extending from your horizon due north, through your zenith, to your horizon due south

the path traced by the Moon's shadow on Earth during a solar eclipse

The angular distance between those two bright stars in the sky is about 2 meters.

The angular distance between those two houses in the distance is 30 degrees.

You can use your outstretched hand against the sky to estimate angular sizes and angular distances.

The angular size of the Sun is about the same as that of the Moon.

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 6/9

Part A - If we have a new moon today, when we will have the next full moon?

ANSWER:

Retrograde Motion

Part A - Explain what planetary retrograde motion is. What does it look like? Why does it occur?

ANSWER:

Parallax

Part A - How would a star's  parallax change as its distance from Earth increases?

ANSWER:

The Seasons: What if Earth’s Axis Tilt Were Different?

Learning Goal:

To understand how seasons would be affected by a greater or smaller axis tilt.

Introduction. What would happen to our seasons if Earth’s axis tilt were different from its actual 23.5°? This activity will help you answer this question and will also help you understand seasons on planets that have axis tilts different from Earth’s. As you examine the diagrams in parts A and B, keep in mind that Earth is always rotating, even though the diagrams do not show this rotation because they are not animated.

Part A - Each of the following figures shows Earth with a different axis tilt. (Assume that Earth’s rotation period is unchanged.) Each also shows a person located in Florida (not to scale). Rank the figures based on how much time the person spends in daylight  during a 24 hour period, from most (Left) to least (Right).

You did not open hints for this part.

ANSWER:

in about 6 months

in about a month

in about 2 weeks

in about 1 week

3785 Character(s) remaining

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The parallax shift does not change; it is independent of the star's distance from Earth.

The parallax shift increases as the star's distance from Earth increases.

The parallax shift decreases as the star's distance from Earth increases.

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 7/9

Part B - The following figures are the same as those from Part A. This time, consider the seasonal differences that occur as Earth orbits the Sun with the different axis tilts. Rank the figures on the basis of the seasonal temperature differences you would expect between summer and winter, from the one with the most extreme seasonal differences (Left) to the one with the least extreme (Right). To rank items as equivalent, overlap them.

You did not open hints for this part.

ANSWER:

Part C

Based on what you have learned from your rankings in Parts A and B, which of the following planets would you expect to have seasons most like Earth’s?

You did not open hints for this part.

Reset Help

Reset Help

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 8/9

ANSWER:

Part D

Which of the following planets should have the most extreme seasons?

You did not open hints for this part.

ANSWER:

Part E

Which of the following planets has essentially no seasons at all?

You did not open hints for this part.

ANSWER:

Beijing & Philadelphia

Part A - Beijing and Philadelphia have about the same latitude but very different longitudes. Therefore, tonight's night sky in these two places:

ANSWER:

Mooned Again

Part A - A week after full moon, the Moon's phase is:

ANSWER:

Uranus (axis tilt = 97.9°)

Mars (axis tilt = 25.2°)

Jupiter (axis tilt = 3.1°)

Neptune (axis tilt = 29.6°)

Jupiter (axis tilt = 3.1°)

Mars (axis tilt = 25.2°)

Uranus (axis tilt = 97.9°)

Neptune (axis tilt = 29.6°)

Mars (axis tilt = 25.2°)

Jupiter (axis tilt = 3.1°)

Uranus (axis tilt = 97.9°)

will look about the same.

will have partially different sets of constellations.

will have completely different sets of constellations.

1/27/2019 Homework 2

https://session.masteringphysics.com/myct/assignmentPrintView?assignmentID=7008141 9/9

Seasonal Temperature Variations

Part A - Explain why summer is hotter than winter. If you find that it would help to include a diagram, e-mail it to your instructor and refer to it in your explanation.

ANSWER:

Score Summary: Your score on this assignment is 0.0%.

You received 0 out of a possible total of 63.5 points.

first quarter.

third quarter.

new.

3785 Character(s) remaining

Essay answers are limited to about 500 words (3800 characters maximum, including spaces).

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