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Freedman and Kaufmann - Universe 8/e (Homework)

James Finch

Astronomy, section 1, Fall 2010

Instructor: Dr. Friendly

Current Score : 2 / 25

Due : Monday, December 6, 2010 08:00 EST

About this Assignment

Question
Points
1 2 3 4 5 6 7
0/1 1/3 0/3 0/2 0/6 0/1 1/9
Total
2/25 (8.0%)

Description

Here are some textbook questions from Universe 8/e by Roger Freedman and William J. Kaufmann published by W. H. Freeman. Click here for a list of all of the questions coded in WebAssign.


Instructions

This demo assignment allows many submissions and makes the answer key available after the first submission so you can see the correct answers. (Typically, the answer key is posted after the due date!)



1. –/1 points Notes Question: FKastro8 1.AQ.24.
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The diameter of the Sun is 1.4 multiplied by 1011 cm, and the distance to the nearest star, Proxima Centauri, is 4.2 ly. Suppose you want to build an exact scale model of the Sun and Proxima Centauri, and you are using a basketball 40 cm in diameter to represent the Sun. In your scale model, how far away would Proxima Centauri be from the Sun?
Enter a number.
 km

2. 1/3 points All Submissions Notes Question: FKastro8 2.AQ.28.
Question part
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0/1 0/1 1
1/50 1/50 1/50
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1/3
 
On November 1 at 11:40 p.m. you look toward the eastern horizon and see the bright star Bellatrix rising. At approximately what time will Bellatrix rise two weeks later, on November 15?
Enter a number.
Your answer is incorrect. :
Enter a number.
Your answer is incorrect. Your answer is correct.

3. –/3 points Notes Question: FKastro8 3.AQ.31.
Question part
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0/1 0/1 0/1
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0/3
 
(a) The Moon moves noticeably over the space of a single night. To show this, calculate how long it takes the Moon to move through an angle equal to its own angular diameter (1/2°) against the background of stars. Give your answer in hours.
Enter a number.
 hours

(b) Through what angle (in degrees) does the Moon move during a 4 hour night?
Enter a number.
°
Can you notice an angle of this size? (Hint: See the figure below.)
    



4. –/2 points Notes Question: FKastro8 4.AQ.49.
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0/1 0/1
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0/2
 
Suppose a newly discovered asteroid is in a circular orbit with synodic period 1.84 years. The asteroid lies between the orbits of Mars and Jupiter.
(a) Find the sidereal period of the orbit.
Enter a number.
 years

(b) Find the distance from the asteroid to the Sun.
Enter a number.
 AU


5. –/6 points Notes Question: FKastro8 18.AQ.37.
Question part
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1 2 3 4 5 6
0/1 0/1 0/1 0/1 0/1 0/1
0/50 0/50 0/50 0/50 0/50 0/50
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0/6
 
(a) Determine the radius of the circumstellar accretion disk in the figure below. (You will need to measure this image with a ruler. Note the scale bar in this figure.) Give your answer in astronomical units and in kilometers.
Enter a number.
 AU
Enter a number.
 km

(b) Assume that the young star at the center of this disk has a mass of 1 Msun. What is the orbital period (in years) of a particle at the outer edge of the disk?
Enter a number.
 yr

(c) Using your ruler again, determine the length of the jet that extends to the right of the circumstellar disk in the figure below.
Enter a number.
 AU
Enter a number.
 km

At a speed of 202 km/s, how long does it take gas to traverse the entire visible length of the jet?
Enter a number.
 yr


6. –/1 points Notes
Question part
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In which region of the HR diagram would our Sun most likely appear 5 billion years from now.



7. 1/9 points All Submissions Notes Question: FKastro8 5.QCQ.02.
Question part
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1 2 3 4 5 6 7 8 9 10
0 0/1 0/1 0/1 1 0/1 0/1 0/1 0/1 0/1
1/50 1/50 1/50 1/50 1/50 1/50 1/50 1/50 1/50 1/50
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1/9
 
Quick Check Quiz - Kirchhoff's Laws

1. Each chemical element produces a unique emission or bright-lined spectrum.
    

Your answer is correct.

Correct. This is true, since the unique electron structure of each element results in a unique spectrum.
2. A hot dense gas produces a dark-lined absorption spectrum.
    

Your answer is incorrect.


Incorrect.
3. Red stars are always hotter than yellow stars.
    

Your answer is incorrect.


Incorrect.
4. Comparing the spectra for a blue star and a red star of equal size, the blue star
    

Your answer is incorrect.


Incorrect.
5. In the emission spectrum for sodium, two bright yellow lines are visible. As the temperature of the sodium increases, these lines
    

Your answer is correct.

You observed the emission lines increasing in intensity in the first 'Background' animation.
6. The average temperature of Mars is lower than that of Venus. If an observer measures the spectrum of infrared radiation coming from each planet, what would she discover?
    

Your answer is incorrect.


Incorrect.
7. Some stars have no atmosphere. The light emerging from its surface would still have the typical stellar absorption line spectrum.
    

Your answer is incorrect.


Incorrect.

8. The image on the first page of Chapter 5 shows the Ring Nebula. Which type of spectrum do you think the Nebula has?
    

Your answer is incorrect.


Incorrect.
9. A star having a temperature of 3000K emits mostly
    

Your answer is incorrect.


Incorrect.
10. The Sun's spectrum, as observed from Earth, is classified as
    

Your answer is incorrect.


Incorrect.

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