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Freedman and Kaufmann - Universe 8/e (Homework)

Chris Read

W.H. Freeman, section 1, Fall 2010

Instructor: Mr. Freeman

Current Score : 0 / 25

Due : Wednesday, September 1, 2010 06:30 PM EDT

About this Assignment

Question
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0/1 0/3 0/3 0/2 0/6 0/1 0/9
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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 10 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. –/3 points Notes Question: FKastro8 2.AQ.28.
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On November 1 at 10:00 p.m. you look toward the eastern horizon and see the bright star Bellatrix rising. At approximately what time will Bellatrix rise one week later, on November 8?
Enter a number.
 :
Enter a number.

3. –/3 points Notes Question: FKastro8 3.AQ.31.
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(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 8 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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Suppose a newly discovered asteroid is in a circular orbit with synodic period 1.22 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.
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(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 280 km/s, how long does it take gas to traverse the entire visible length of the jet?
Enter a number.
 yr


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In which region of the HR diagram would our Sun most likely appear 5 billion years from now.



7. –/9 points Notes Question: FKastro8 5.QCQ.02.
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Quick Check Quiz - Kirchhoff's Laws

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


2. A hot dense gas produces a dark-lined absorption spectrum.
    


3. Red stars are always hotter than yellow stars.
    


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


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


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?
    


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



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


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


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



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