## 20140318

### Online reading assignment: Kirchhoff's laws (NC campus)

Astronomy 210, spring semester 2014
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on Kirchhoff's laws.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"I found it interesting that the Doppler effect could be used for both sound and light waves."

"It's cool that light from a star can tell so much about its position and movement."

I found the Doppler effect interesting because it was something so familiar to me that finally had a name. Also, I now envision sound waves as colors (blue for high pitch / red for low pitch) when listening to cars pass by."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The spectra were a little confusing because I can understand the pictures of the wavelengths, but I not sure how to determine which objects produce which types of spectra."

"I just need the redshift/blueshift explained a bit more in detail, but other than that I am A-OK."

"I get the Doppler effect in terms of sound. But when the presentation started talking about blueshift and red shift it got a little fuzzy."

I believe Pluto should be a planet.
 Strongly disagree. ** [2] Disagree. *** [3] Neutral. ************ [12] Agree. *** [3] Strongly Agree. [0]

Briefly explain your answer to the previous question (whether Pluto should be a planet).
"I don't think it's possible that Pluto can remain a planet anymore. it doesn't meet the requirements anymore, and that's not a bad thing! We still love you Pluto!"

"Now I know that Pluto does not dominate its own orbit therefore it should not be a planet."

"Pluto should be a planet but learning more about Pluto, it doesn't fit what planets are suppose to be now."

"I feel bad for Pluto, but I guess you can't let Pluto slide unless you are willing to make exceptions for all the other dwarf planets. Or risk some kind of dwarf planet anarchy."

"I've always believed Pluto was a planet when I was younger...because it was a planet. but now that it is classified as not a planet I don't really mind it. And it also doesn't fit into the IAU's criteria to be a planet."

"If it doesn't pass the planet test, its not a planet."

"If we allow the old standards to determine planets then there would be an excess of planets. In the search for new planets and life it would behoove us to narrow the scope. I can always look back and remember when I once knew Pluto as just another planet in our solar system."

Suppose you are standing on the sidewalk as a car, with its horn continuously on, passes by (video link). The loudness of the car horn:
 starts high, then drops lower. **** [4] starts low, then goes higher. ** [2] starts low, goes higher, then drops back down to low. ************** [14] starts high, goes lower, then goes back up to high. [0] (Unsure/guessing/lost/help!) [0]

Suppose you are standing on the sidewalk as a car, with its horn continuously on, passes by (video link, same as above). The pitch (high note/low note) of the car horn:
 starts high, then drops lower. ******** [8] starts low, then goes higher. *** [3] starts low, goes higher, then drops back down to low. **** [4] starts high, goes lower, then goes back up to high. *** [3] (Unsure/guessing/lost/help!) ** [2]

Match the spectrum type with their apperance.
(Only correct responses shown.)
Rainbow containing all colors: continuous [95%]
Rainbow with thin black lines: absorption [85%]
Colored lines on a black background: emission [84%]
Given off by hot, dense object: continuous [90%]
Given off by hot, diffuse gas atoms: emission [95%]
Passing through cool, diffuse gas atoms: [95%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I guess I just wanted to clarify that electrons will always emit after they are excited?" (Yes, if they are in an upper energy level, they will eventually go back down by emitting a photon.)