Homework Due Tuesday March 29

Take a look at the "Total DP Curriculum" and all that we have left to cover.  Yes, we really have that much left!!! 

Post a comment suggesting at least 3 ways for us as a class to improve our efficiency as well as you individually to improve your efficiency in studying and learning.  The more efficiently you study and learn, the better your understanding will be and as a result, we can move faster through the material.

Your suggestions need to be concrete steps that can be taken...
For example, "I will study more" is not concrete enough.  Instead, you could say,
"I will spend 30 minutes each day reviewing my class physics notes and adding additional notes and comments to them"

Homework Due Monday Mar 28

1) Finish all homework that was due on Friday.  Don't forget to comment:start, doubts, finish!

2) Those of you who haven't sent me your one-page study plan need to do so by tonight (Sunday night).  Aman, your one-sentence comment doesn't count.

3) FUN SHEETS!  Fill out a new "what I will do" fun sheet. And go back to the last "what I will do" sheet that you filled out a long time ago and highlight all the things you said you'd do but didn't do in red.  EMAIL ME TONIGT

Homework Due Friday March 25

Post comments - when you start, doubts, and when you finish
If the comments don't go through, email me.  If your internet is not working, sms me your comments.
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1) Finish all "Questions for Thought" questions
Think about each question and all that it is asking.  Refer to your class notes and the textbook to ensure that you completely understand the subject material.  Write a thorough and complete answer to the question.  Remember what we discussed in class and how best to earn full marks on IB questions.  Write your answers as though you were giving them on an IB exam.

2) Answer the following questions from the "Light" documents

39) The light ray model is used to describe which laws?  Explain how this model accounts for certain properties and behaviors of light.

40) How does light interact with dust in the air?

41) Explain why, even though a table blocks light that falls on it from above, we are still able to see under the table (it is shaded under the table yet not completely dark).

42) If vertical light rays (i.e. light rays that hit straight on making a 90 degree angle with the object) strike a transparent object, describe what happens to the rays in detail.  3 things will happen – describe each thing clearly.

43) Explain the relationship between transmission and refraction.

44) Explain why you can partially see your own reflection in a glass window when it’s dark outside the window.

45) What is a normal line with respect to a reflecting surface?  Draw a sketch.

46) Suppose a block is x centimeters from a mirror.  I can see the reflection of the block in the mirror.  How far behind the mirror does the “virtual image” of the block appear to be?

47) What are diverging rays of light?

48) Give an example of a virtual image and a real image.

49) Which type of mirrors are used to see an object enlarged?

50) What is a reflecting telescope?

51) What causes refraction?

52) Draw a diagram showing a light wave traveling from air to water with some incident angle theta. Show the direction of the refracted light and label the angle of refraction.

53) Draw a diagram showing a light wave traveling from water to air with some incident angle theta. Show the direction of the refracted light and label the angle of refraction.

54) Draw a diagram showing a light wave traveling through air and striking the surface of water at 90 degrees (normal to the surface).  Show the direction of the refracted light and label the angle of refraction.

55) Does light bend more (i.e. refract to a larger degree) when the angle of incidence is large or small?

56) What is fiber optics?

Homework Due Wednesday March 23

1) Submit a one page "Study Plan" for the April physics exam
- Write down each of the topics that will be covered on the physics exam (see the April EXAM Topics page at the top of the main page on the blog)
- Below each topic, write a couple sentences outlining how you plan to study the section and prepare for the exam.  Some ideas for studying: review class notes, review homework sums, ask ma'am for sample IB questions, work examples from the text book etc.
- Next to each topic, write a note about how comfortable you feel with the topic.  Do you understand it well and are you confident that you will score well in it, or do you need to study a lot?

Homework Due Tuesday March 22

Post a comment with your responses:
1) Did I use my time effectively during the day?  Was I productive at school?
2)

Homework Due Friday March 18 - happy now Riya???!!!

Answer the following questions from the "Light" documents:
Don't forget to post a comment saying you've started working on the questions and another comment when you finish the questions.

31) Explain: “As a model, think of bundles of light rays entering your eye, which enable you to see the tree from any angle because different bundles of reflected rays will enter your eye from different parts of the tree.”

32) Explain the difference between the direction reflected light takes from smooth surfaces and rough surfaces.

33) Write the “Law of Reflection.”

34) What are “diverging rays”?

35) Explain what a virtual image is in your own words (don’t copy from the book).

36) Describe the difference between concave and convex mirrors.

37) What happens when light travels from one medium to another? Give one to two sentences of a detailed answer.

38) Why are light rays refracted?

 Read the Quantum Theory 2 and 3 documents and take a minimum of 2 pages of notes.

Answer the following questions about the Quantum Theory docs:

1) Explain the quote by Richard Feynman on the very first page of the Quantum Theory 2.  Give an example of something which doesn’t produce the same results given the same conditions.

(p. 15)

2) What is a protogalaxy? (p. 15)

3) What is feeble light? (p. 15)

4) Explain: “tiny particles of light raining down on the telescope’s detectors from the very depths of space.”  What are the particles and where did they come from? (p. 15)

5) What does it mean for astronomers to be “straining to see the weakest sources of light from the universe”? (p. 15)

Homework Due Monday Mar 21

1) Get a clear bag/file/folder and stock it with blank sheets of paper to keep with you in your bag at all times.  BRING IT TO CLASS ON MONDAY.  Don't forget!!!


2) Bring your almanac or some kind of diary/calendar.  BRING IT TO CLASS ON MONDAY.  Don't forget!!!

3) FUNNNN SHEETS!!  Yes, I know how much you love your "what i did, will do sheets"!  Go over the sheet you sent me from last week - the "what i will do sheet."  Highlight all the things you said you were gonna do but didn't do this week in red.  Then make a new "what i will do sheet" for next week.  EMAIL ME SOON - latest by Sunday night, but do it as soon as possible.  And really put some thought into it.

4) Reading Assignment: 2 pages notes (the reading covers topics we've already learned about so it should be a good review)
SL: p. 380 - 396
HL: p. 411 - 420, 424 - 428 (end at 12.4), 432 - 434 (end at 12.7)

5) Sums
SL: p. 382 1-3, p. 384 4-7, p. 385 8-9
HL: p. 413 1-3, p. 415 4-7, p. 416 8-9

Homework Due Wednesday Mar 16

Questions from Light chapter

1) Explain why, unlike matter, we can only study light indirectly.

2) “Light cannot be directly observed” – give your thoughts and ideas on what this means.

3) What does it mean for something to be difficult to “pin down”?

4) What is a “baffling dilemma”?

5) Explain this sentence, “Evidence for accepting a wave or particle model seems to depend on which experiments are considered.”

6) What is refraction?

7) List the three models used to describe the behavior of light and explain when each model is applicabable.

8) Explain this sentence “The acceleration produces a wave consisting of electrical and magnetic fields that become isolated from the accelerated charge, moving off into space.”

9)  The greater the acceleration of a charge, the ____ (higher or lower) the wavelength of the emitted light?

10) What does it mean for visible light to occupy the “middle portion” of the electromagnetic wave spectrum?

11) What is an “idealized” material?

12) What determines how much energy is available to accelerate charged particles?

13) What does it mean for all electromagnetic waves to have the “same fundamental character”?

14) Explain this sentence, “A graph of the frequencies emitted from the range of available energy is thus somewhat bell-shaped.”

15) Which is brighter, a very hot object or a medium-hot object?  Use Figure 4 to explain.

16) Explain why, based on your knowledge of movement of molecules in a “hot” object, hotter objects emit higher frequency radiation.

17) Estimate the frequency of peak radiation for objects at 6,000 K.

18) Which would be brighter (i.e. have higher intensity) – an burning object that looks blue or a burning object that looks yellow?

19) Why can burning objects appear to be red, but not appear to be violet?

20) If burning objects can’t emit light, then why does hydrogen emit violet light?

21) Which is broader relative to its height, the radiation spectrum for 6,000 K objects or for 4,000 K objects?

22) Given that light from the sun takes 8 minutes to travel to the surface of the earth, calculate the distance between the sun and the earth’s surfaces.

23) What does it mean to say “there are limits to using a light ray for explaining some properties of light”?

24) At an atomic and molecular level, what do you think a perfectly smooth surface is?

25) List the three ways in which light interacts with matter.

26) Explain this sentence “Any combination of these interactions (reflection, absorption, transmission) can take place but a particular substance is usually characterized by what it mostly does to light.”

27) Explain “Absorbed light gives up its energy to the material and may be reemitted at a different wavelength or it may simply show up as a temperature increase.” 

28) If absorbed light gives its energy to a material and is then reemitted at a different wavelength, would the wavelength of the reemitted light be larger or smaller than the original light?  (HINT: think about energy of light waves and the amount of energy carried by long and short wavelength light)

29) “Vertical rays of light… are mostly transmitted through a transparent material with some reflection and some absorption.”  Draw a diagram to show what this might look like (include the vertical rays and the transparent material – be sure to draw the path of the rays)

30) Explain why there is a “glare” of sunlight around a body of water.

Homework Due Tuesday March 15

1) Answer the following questions TONIGHT (Monday, March 14) by commenting on your personal page
1) How productive was physics class today?  Explain in a sentence or two whether you felt the speed at which we moved was adequate, whether we discussed enough topics and problems etc.
2) Did you give your full attention to the class?  Do you feel you left the class having accomplished a lot?
3) Did you use your time productively during the rest of the day? Be honest with yourself - (there were a few gaps of time between classes and some of you had free 7th periods).
4) Divya and Deshal, what did you do during 7th period today?

Homework Due Monday Mar 14

Put your NAME and the DATE DUE on all assignments. 


1) Fill out the "What I've Done" and "What I will do" (for this past week and next week respectively) and email me by SUNDAY NIGHT.  DO NOT FORGET *grrrrrrrr*


2) Post a comment on the blog when you begin working on the assignment "I've begun the assignment"


3) Answer the questions below pertaining to the "Atomic Theory" documents

1) What is a standing wave?

2) What is the new model of the atom which replaced the Bohr model?

3) Explain this sentence: “Instead of the simple circular planetary orbits of the Bohr model, solving the Schrodinger equation results in a description of three-dimensional shapes of the patterns that develop when electron waves are confined by a nucleus.”

4) A man weighs 60 kg.  How fast must he travel in order for his wavelength to match that of red light?

5) Describe the experiment which shows that electrons have wave properties.

6) Contrast the orbits of the Bohr model to the orbits of Shrodinger’s model.  Describe the motion of electrons and the shape of the orbits.

7) What does the following mean: “A wave is not localized like a particle.”

8) What is meant by a “fuzzy electron cloud”?

9) Explain: “The quantum mechanical theory is not an extension or refinement of the Bohr model.”

10) In the quantum-mechanical model, the electron is considered to be a spread-out wave.  Where exactly then are the electrons located?

11) The higher the energy of the electron, the _____ (nearer or farther) the electron is to the nucleus.

12) List the names of the four quantum numbers.

13) Write the electron configuration for fluorine.

14) List the three orbitals which come after 2p.

15) What is a “cell” of the periodic table?

16) Explain this sentence “The arrangement has a meaning, both about atomic structure and about chemical behaviors.”

17) What does “facilitate your understanding” mean?

18)  Nitrogen has more similarities to _______ (oxygen or phosphorus)?

19) Give an example of a very soft, shiny metal which is highly reactive with water.

20) List all elements described in the text book as “reactive” (includes both metals and non-metals).

21) What does “inert” mean?

22) How many electrons are in the outer-most orbital of tin?

23) The electrons of which orbitals are responsible for chemical reactions?

4) Read Light Document 1 and take a minimum of 2 pages of notes.  Follow the *special* note guidelines below.
Remember the process for how to read text books that we discussed in class?  Try it out today when you read the light document!  Start by reading the chapter outline, scanning all headings throughout the reading and glancing at the diagrams.  Write your thoughts and questions as you get an oveview of the chapter. I want to see TONS of questions written down!  As always, make note of new vocabulary words. Write something like this:


First-over scan of the chapter:
Outline - sources of light
In class we've only talked about light coming from accelerating charged particles and also about light being emitted by all objects due to their temperature - I'm wondering what types of light sources will be discussed in the book
Key words in bold -
incandescent - we read about this
black-body radiation - I've heard of this
Headlines - "Light Interacts with Matter" - I don't know much about this at all

5) Read Light Document 2 and take a minimum of 2 pages of notes.  Follow the *special* note guidelines.

Homework Due Friday Mar 10

1) Post a comment saying that you've started working on the homework due Friday

2) Answer the following questions for "Atomic Theory Phys Sci" documents.  Each one of you should post your answer to the problem assigned to you.  This way I know what time you reached that question :P
Aman - 19
Riya - 13
Divya - 14
Deshal - 18

1) An incandescent gas emits only certain colors.  What happens if we change the temperature of the gas? (p. 210)
2) In your own words, what does "intensity" (of light) mean? (p. 210)
3) Explain this sentence, "...an accelerating electron should emit an electromagnetic wave such as light, which would move off into space from the electron." (p. 212)
4) Bohr "postulated this rule as a way to make his theory consistent with other scientific theories." What is "this rule" and what are the "other scientific theories"? (p. 212)
5) Why are the orbits called "radiationless" (p. 212)
6) What is a quantum leap? (p. 212)
7) Explain why an electron jumping from a high energy state to a low energy state emits higher frequency light than an electron which jumps from a medium energy state to a low energy state. (p. 212) 9898001471 sunil duvai
8) Think of gravitational potential energy.  Objects held above the surface of the earth have a certain amount of potential energy.  The further we move the object away from the earth, the higher the potential energy of the object.  Is this situation analogous to the potential energy of an electron in an atom?  Why or why not?  Explain in detail. (p. 212)
9) Would it take more work to remove an electron from the n=3 orbit (i.e. pull the electron all the way out of the atom) or from the n=5 orbit? (p. 212)
10) Could an electron in a hydrogen atom have -1.82 eV of energy? (p. 212)
11) Is the energy of light proportional or inversely proportional to the frequency of the light?  Give the equation relating energy to frequency. (p. 213)
12) If a container of mercury atoms are exposed to a potential, what type of light do they emit? (p. 213)
13) Suppose I had a container of hydrogen gas and I only wanted it to emit red light.  Suggest some possible ways of achieving this.  (p. 212)
14) Now suppose I wanted the hydrogen gas to emit yellow light.  Is this possible?  If so, how could I accomplish this? (p. 212)
15) What type of light does hydrogen emit if n=8? (p. 211)
16) What does the "single quantum number" of Bohr's model refer to? (p. 213)
17) What does de Broglie mean by "symmetry found in nature"? (p. 214)
18)   Suppose that the circumference of a particular orbit is 3x10^-10 m.  Give three possible wavelengths for standing electron waves that could fit in the orbit. (p. 214)
19) Since all matter has a wavelength associated with it, which particle traveling at the speed of light has a larger wavelength - an electron or a photon? HINT: look at de Broglie's equation (8.5) to see the relationship between mass and wavelength and then think about which is heavier, electron on photon.

3) Do the following MCQs at the end of the 4th Atomic Theory doc
Aman - 4, 8, 12, 16, 20, 24, 28
Riya - 1, 5, 9, 13, 17, 21, 25, 29
Divya - 2, 6, 10, 14, 18, 22, 26, 30
Deshal - 3, 7, 11, 15, 19, 23, 27, 31

Homework Due Wednesday Mar 9

This is a LOT of homework - do all of it all of it all of it by Wednesday lunch.  I won't accept any work after Wed. lunch.  I'll check all the homework after lunch and if anything is missing, then you'll have to stay after!  Good luck *mwah-ha-ha-ha* ;)
 
1) Bring your almanac to school on Wed.

2) Since no one's done it yet...
Go back to your "What I Will Do" (yes, I know, your absolute favorites!) sheet (which you sent me last week) and highlight in red any of the things you said you'd do this week but didn't.  Email me by Sunday night.

3) Become a follower of the blog
Once you become a follower make a comment on this post "I worship the physics blog" - this way I can keep tabs on when you check the blog and start the homework ;)

4) Complete the entire Atomic Phys Sci readings (4 documents). Write a page of "review" notes over the entire Atomic Phys chapter (in addition to the previously assigned 4 pages of notes - see hw due Monday).
Your review notes should summarize all the ideas in the chapter and explain how they relate to each other.  It's a sheet on which you can clarify the concepts in your head and make sense of all of them.

5) Do the following multiple-choice sums assigned to each of you at the end of the Atomic Phys chapter (document 4).  Write a sentence or two (or show calculations) explaining how you got the answer for each sum.
Aman - 1, 5, 9, 13, 17, 21, 25, 29
Riya - 2, 6, 10, 14, 18, 22, 26, 30
Divya - 3, 7, 11, 15, 19, 23, 27, 31
Deshal - 4, 8, 12, 16, 20, 24, 28
6) Read "The Mighty Atom 3" and take a minimum of a page of notes.  Include 5 new vocabulary words and their definitions.
1) Neils Bohr was described as "mild and affable."  Explain what that means. (p. 176)
2) What is a landmark paper? (p. 176)
3) The idea of the "quantum leap... kept electrons from spiralling catastrophically into the nucleus."  Firstly,what does catastrophic mean?  Explain why electrons not being allowed to occupy regions outside of set orbits means that they won't spiral into the nucleus. (p. 176)
4) Why were hydrogen's wavelengths "bewildering" to scientists? (p. 176)
5) Explain how neutrons are essential to making atom bombs.  (You can look up some info on the internet if you need) (p. 177)
6) Who was Rutherford's predecessor at the Cavendish Laboratory? (p. 177)
7) Neutrons were elusive and long-sought particles (see the picture caption titled "below").  What does this mean? (p. 177)
8) How is the fact that electons sometimes behave like particles and sometimes like waves an "impossible duality"? (p. 178)
9) Explain the following "certain anomalies in the behaviour of electrons disappeared when on thought of them as waves." (p. 178)
10) What is a "deft refinement"? (p. 178)
11) What is an immutable property of the universe? (p. 179)
12) "An electron doesn't exist unless it's observed."  How might this statement shed light on the age-old philosophical question - "if a tree falls in the forest but no one is there to hear it, does it make a sound?" (p. 179)
13) "The electron... takes on the more amorphous aspect of a cloud."  Explain.
14) Scientists encountered "an area of the universe that our brains just aren't wired to understand."  What does it mean for our brains to be "wired" to understand something? (p. 180)

Homework Due Monday Mar 7

1) Bring your school almanac (calendar book), your file/folder containing all physics homework, and all class notes you've taken during the past two months (they may be in a couple notesbooks)

2) Go back to your "What I Will Do" (yes, I know, your absolute favorites!) sheet (which you sent me last week) and highlight in red any of the things you said you'd do this week but didn't.  Email me by Sunday night.

3) Read the two documents I sent by email "Atomic Theory Phys Sci 3" and "Atomic Theory Phys Sci 4" and take a minimum of 4 pages of notes

4) Answer the followig questions from the "Atomic Theory Phys Sci 1" reading assignment:
1) Consider the sentence, "If the mass of the hyrogen atom is due to the electrons embedded in positively charged matrix..." What is the meaning of "a positively charged matrix"?  (p. 208)
2) Continued from last question... If there were 1,840 electrons in a hydrogen atom, then what would the "glob of positive charge (p. 208)
3) Explain what it means for electrons to move around the nucleus at a distance 100,000 times the radius of the nucleus
4) Throughout this topic, we've been learning about how scientists studying matter and energy in the 1800s and 1900s made models to describe natural phenoma.  The scientists were then able to fine-tune (or change) their models after collecting new experimental data.  Think about scientists today - they must too have theories and models that describe how nature works.    There are millions of scientists in the world running millions of experiments everyday.  How often do you think experiments lead scientists to change their ideas about how nature works?  And with the millions of experiments that are taking place daily, how quickly do you think science is growing and changing?
4) As we've been learning, once upon a time, people weren't sure if matter was made of some continuous medium or if it was made of discrete particles called atoms.  Then experimental evidence revealed that atoms do exist.  Give examples of other things we've been reading about that were thought to have possibly been "continuous" but were in fact found to be "discrete." (I can think of 4 examples)
5) Using the mass of the H atom in atomic mass units and the mass of the H isotope (with one neutron) in atomic mass units, determine the mass of a single neutron (in atomic mass units).  Then find the mass of the neturon in kg (by converting from a.m.u to kg).  Does your answer agree with the accepted value of the neutron mass? (p. 209)
6) Calculate the atomic weight of oxyen.  Refer to Table 8.1 for the needed values and to compare your final answer.  Show all work in doing the calculations. (p. 209)
7) What is spectroscopy? (p. 210)
8) What is an incandescent gas? (p. 210)
9) Which forms of matter give off continuous spectra and which forms of matter give off discrete spectra? (p. 210)
10) What the key differences that allow some forms of matter to give off continuous spectra and other kinds to give off discrete spectra (p. 210)

5) Answer the followig questions from the "Atomic Theory Phys Sci 2" reading assignment:
1) Describe how we might be able to determine the elements making up a star by looking at line spectra. (p. 211)
2) In the Balmer Series, which violet line has more energy, n=5 or n=6? (HINT: look at the wavelenghth of the light and figure out whether longer or shorter wavelengths of light have more energy)
3) We know that hydrogen atoms do not emit light when in their "normal state."  Under what conditions do they emit light?
4) Based on what's written in the "Allowed Orbits" section, suppose that I find that a particular atom (this is just an exercise and the proportions given are completly unrealistic) has orbits located at the following distances from the nucleus: orbit a) 1 cm; orbit b) 1.5 cm; orbit c) 3 cm.  Draw a diagram and label the orbits and their distances from the nucleus.  Which orbit has the highest energy?

Homework Due Friday Mar 4

1) Read all pages sent by email and answer the following questions:

1) How did the discovery of radioactivity lead to the discovery of protons and neutrons? (p. 206)

2) Explain how the solar system model of the atom had initial but limited success (p. 206)

3) What is an optical microscope? (p. 206)

4) What does it mean to “infer” something from experimental evidence? (p. 206)

5) What is a plausible idea? (p. 206)

6) List the two “plausible ideas” postulated by the Greeks about the structure of water in your own words (p. 206)

7) What does it mean for water to be homogenous throughout? (p. 206)

8) Who were Plato and Aristotle? (p. 206)

9) “Indivisible minute particles called atoms make up all matter.”  What are minute particles? (p. 206)

10) Why is the second statement in Dalton’s Atomic Theory not technically correct? (p. 206)

11) Give an example of a compound that illustrates statement 4. (p. 206)

12) What does this sentence mean “there was skepticism about something that could not be observed directly”? (p. 206)

13) Describe the irony in the fact that the existence of atoms came to be accepted in the early 1900s after it was discovered that atoms have parts. (p. 206)

14) Thomson found that all cathode rays are composed of particles with a fixed charge to mass ratio that is independent of the material from which the cathode rays came.  Suppose that Thompson had discovered that the charge to mass ratio of cathode ray particles varied depending on the material of the electrodes.  Would his conclusions about electrons have been different? (p. 207)

15) Thomson found the charge-to-mass ratio of electrons and Millikan measured the charge of the electron.  Using those two values, find the mass of the electron. (p. 207)