Section

  • You are using a computer and the internet right now and so you are using over 100 phenomena from the physics of electricity and magnetism. We will learn about dozens of those phenomena this year. It is an amazing story.

    HW Tue: summarize the Demo of Charge you did on monday, including a sketch.  Show clearly where the electrons moved.

    HW Wed:  hand in lab notes from electron transfer activity in class on Tuesday.  Include a short description of the set up.  You should report how many electrons are lost per second.  It will be a big number.

    HW Friday: Study and learn the opening section before History in Wikipedia for Electricity (it starts "Electricity is the set of physical phenomena associated with the presence of electric charge").  I will give a reading quiz in class.

    For next Tuesday: 16: Q-1, 2, 3, 4,6; summary of scotch tape static; getting to know the static charge physlets, see below.   (your HW for Tuesday is to open the site and make sure you can run the physlets and show me a printout (not hand-drawn) of each of them.)

            http://phet.colorado.edu/en/simulations/category/physics is the site where you can find most of the physlets we'll use in class. You can select "electricity, magnets, and circuits" to get a shorter list. We'll look at "electric field of Dreams" and "electric hockey" first. Play with this for about 5 minutes.

            Points:

    • know what is difference between doing science and studying science
    • Differentiate science and authority-based systems
    • Be able to define/organize the scope of Phys II vs Phys I
    • Be able to generate positive and negative static charge
    • Be able to draw the topics map and fit in electricity
    • Define and characterize charge

  • For Monday: LABOR DAY HOLIDAY

    For Tuesday: 16: Q-1, 2, 3, 4,6; summary of scotch tape static as assigned in class; Getting to know the static charge physlets, see below.   (your HW for Tuesday is to open the site and make sure you can run the physlets and show me a printout (not hand-drawn) of each of them.)

            http://phet.colorado.edu/en/simulations/category/physics is the site where you can find most of the physlets we'll use in class. You can select "electricity, magnets, and circuits" to get a shorter list. We'll look at "electric field of Dreams" and "electric hockey" first. Play with this for about 5 minutes.

            http://www.compadre.org/Physlets/electromagnetism/  this is another useful page, look at the "electric field" list and open "Field-Line Representation of Vector Fields".  This one will require you use IE or Firefox.  Move the charges around.    Toggle between vectors and lines.  In Config B, can you tell which charges are + and -  ?

    (IMPORTANT NOTE: MANY TIMES, IF AN APP OR PHYSLET DOESN'T RUN ON A COMPUTER, IT IS PROBABLY THE FAULT OF THE WEB BROWSER YOU ARE USING.  SO IF CHROME DOESN'T WORK, TRY INTERNET EXPLORER.  IT IS YOUR RESPONSIBILITY TO FIGURE OUT HOW TO WORK THESE PROGRAMS.)

    HW due Wed: 16: Q-7,8 P-1,2,3, 5, 7, 9     Another good link for static charges that you can run on IE or Firefox:    http://vnatsci.ltu.edu/s_schneider/physlets/main/efield.shtml.  try the various charge configurations, and press play to see the little charge move.

    HW Friday: 16: Q-9, 10, 11; P-13, 15

    HW due next Monday: read 16.7, 16.8; do 16: Q-13,14,15; P-23,25,27,29,33 

    quiz next Tuesday : on Coulomb's Law and forces

    Points:

    • Describe when induction will occur and its effects (on conductors and insulators)
    • Describe conduction and induction cases for electroscope practicum
    • Be able to do simple coulomb’s law calculations
    • Be able to apply vector math to do 2-D coulomb’s law problems
    • Know that Coulomb’s law is complete for electrostatics, not complete for electrodynamics
  • HW due Monday: read 16.7, 16.8; do 16: Q-13,14,15; P-23,25,27,29,33 

    quiz Tuesday : on Coulomb's Law and forces, and for this quiz, memorize the value of k

    HW due Wed: 16: p-17a, 31, 57, 32, 41, 55; and Faraday cage lab memo report  

    HW Due Thursday: using http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml (in IE or Firefox) this link, find all positions in all 7 of the Charge Configurations where the E field is zero.  Be prepared to show the class.  If you place the green test charge at this location, it should not move.

    We will conduct the pith ball minilab on thursday in class.

    HW due Friday:  16: p-11, 26, 62 (use kinematics and F)   Write the hypothesis for the lab, and show me the relation for qtotal as a function of d, m, g, k, and q and calculate a value for q on each pith ball.
    Note, data for the lab in J: drive and I will keep posting new notes on Measuring Coulomb's Law in FILES.

    HW due next Monday:  
    17: Q-1-5; P-1,3,5,7,11;   Show me a draft of the report.  This should be typed and all the parts finished.   use this physlet to prove that Work=0 if you move along an equipotential line for any of the Charge Configurations; bring printed page --  http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml  .

    HW due next Thursday:   The complete formal report of Measuring Coulomb's Law is due.   

    Points:

    1. Be able to describe lightning with physics of charge, induction, and ionization
    2. Sketch field lines for 5 basic cases of charge
    3. Relate electric potential to gravity potential
    4. Relate V to E
    5. Relate equipotential lines to contour (topo) map

  • HW due Monday:  
    17: Q-1-5; P-1,3,5,7,11;      use this physlet to prove that Work=0 if you move along an equipotential line for any of the Charge Configurations; bring printed page --  http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml  .

    HW due Tuesday:  Coulomb pith ball numerical calculation due, using the data you obtained in the lab, will be handed in.  Make your calculation clear and readable.
    Draw E-field lines and equipotential lines for each of these:  1).  2 equal positive point charges  2).  2 positive point charges of 1 and 3 q each  3)  a triangle with a negative point charge at each vertex.   4)  a very long line of charge

    HW due Wednesday: Show me a draft of the Coulomb lab report.  This should be typed and all the parts outlined..  
    An equilateral triangle with sides of 2.0m has a point charge of +1mC at each apex.  a) carefully draw the E field lines and isopotential lines.  b) what is E at the center of the triangle?  c) what is V at the center?

    Thursday. RETREAT

    HW due Friday  RETREAT

    HW due next Monday: Gauss's Law: 16: 39, 41,43,47.  Also, show that Coulomb's Law E=kQ/r2 can be derived from Gauss's Law.  (Recall that k = 1/(4πεo)

    HW due next Tuesday, 26 Sep:   The complete formal report of Measuring Coulomb's Law is due.

    Points:

    • Understand Gauss's law, and use it to derive Coulomb's Law for a point charge
    • Be able to describe lightning with physics of charge, induction, and ionization
    • Sketch field lines for 5 basic cases of charge
    • Relate electric potential to gravity potential
    • Relate V to E
    • Relate equipotential lines to contour (topo) map
  • NOTE: for the exam in one week, you need to recall that F=GMm/r2 and how it is applied.  You don't need to memorize the value of G.

    HW due Monday: Gauss's Law: 16: 39, 41,43, 47.  Also, show that Coulomb's Law E=kQ/r2 can be derived from Gauss's Law. -- Recall that k = 1/(4πeo)  YES, we did this in class, so if your notes are neat and legible, show me that.  If not, then write it neatly for me to review.  

    HW due Tuesday, 26 Sep: The complete formal report of Measuring Coulomb's Law is due

    HW due Wednesday: you are off somewhere learning about college.   The study guide is posted.  

    Thursday: 16: Q-22 and P-67. chapter 17: MCQ-1,2,3,4,5,6; p-8, 13  and you didn't show me this, so be prepared.   use this physlet to prove that Work=0 if you move along an equipotential line for any of the Charge Configurations; bring printed page --  http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml 

    quiz: given a charge, you will calculate properties of field or potential.  

    HW due Friday:  Do chapter 16 MCQ 1-13 (all of them); write each of chapter 16 classic problems on a page and make a diagram for each.   Slides for both 16 and 17 will be posted.

    HW due next Monday: Exam 1 in class.  It covers up through section 5 in chapter 17.

    For fun only, use the Davidson physlet to test if you can put the test charge into orbit around a single or multiple negative charges, or can you make the test charge hover in one place?.  (double click to create new equipotential lines) bring in a printout 

    If you're really good, you can show that the particle bounces between the same value potential lines.

    points.

    • Be able to describe lightning with physics of charge, induction, and ionization
    • Name and sketch the 10 main problems for the exam.
    • Sketch what happens to an insulator in an E field
    • Show how to quantify V from a point charge in space
  • some thoughts about repulsive charges:   http://what-if.xkcd.com/140/

    Monday: exam 1.   bring two colors of pencil.

    HW due Tuesday:  17: Q:6,7,8,9; P-2,4,6,10  

    HW due Wednesday: 17:P-15, 17, 19, 21, 23, 25 use this physlet to put the test charge into orbit around a single or multiple negative charges, or can you make the test charge hover in one place?.  (double click to create new equipotential lines) bring in a printout  http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml   

    HW due Friday:  17: Q-10,18; P-35, 37

    HW due next Monday:.17: P-39, 43, 49, 53, 57 

    NEXT TUESDAY: 17:q-11, 12; P-68,69,71,73,74,77 (be sure to consider all positions on the line)  Also, calculate the design for a capacitor to hold 1.0nC using only a AA battery and one two layers of metal separated by a sheet of plastic wrate, report area and separation.

    Next week: capacitor lab introduced.

    goals for this week:

    1. describe how a capacitor works
    2. design a capacitor of a given C by adjusting d and A
    3. be able to describe the role and effect of dielectric materials in a capacitor
    4. be able to describe 6 fundamentals of lightning
    5. describe the energy stored in an electric field and quantify it.
  • HW due Monday:17: P-39, 43, 49, 53, 57    
    We will discuss the lab to be conducted on Thursday and Friday

    Due TUESDAY: 17:q-11, 12; P-68,69,71,73,74,77 (be sure to consider all positions on the line)  Also, calculate the design for a capacitor to hold 1.0nC using only a AA battery and two layers of aluminum foil separated by a sheet of food plastic wrap: report area and separation

    Wednesday:  PSAT for 11th grade

    HW due Thursday: Two groups will perform lab in class .  Your prelab is due as soon as you walk in the lab.

    • This HW you will work on when not doing the lab these two days.
    • 17: P-45, Search&Learn (S&L) p 500: #3 on lightning; and read 18 sections 1-3,
    • show problem 77 a and b using the physlet below, sketch on printout the elevation of the potential as we did in class, bring printout to class;    then do the same for two equal negative charges, bring printout.
    • http://vnatsci.ltu.edu/s_schneider/physlets/main/equipotentials.shtml

    HW due Friday: Your first reading assignment is due for hand in.  You should read and report on chapter 2 of WHNI.  See the handout if you are confused.
    Two more groups will work on the lab, and others will review HW and lab analysis.  bring your computers if you want to work on your lab.

    HW due next Monday: 18: Q-1,2,3,4,5; MCQ-1,3,4,5; P-1,3,5  Look at this physlet: http://phet.colorado.edu/en/simulation/capacitor-lab

  • This section

    HW due Monday: 18: Q-1,2,3,4,5; MCQ-1,3,4,5; P-1,3,5  Look at this physlet: http://phet.colorado.edu/en/simulation/capacitor-lab

    HW due Tuesday:  17: P-85, 88, 93 (hint: find the travel time between plates first); also have your data for the lab plotted (each person should have the data and the plots)

    Wed:  Bring a plot of your data as described for parts 1 and 2.  NOTE;  I have attached in files an example of the analysis section for the lab.  You are allowed to cut and paste from this section, and you are free to borrow equations and ideas from it.  I do expect you to understand it and derive your own numbers based on your data.

    Also due Wednedsay: Do these 3 problems below.

    x1: A capacitor of 25mF is charged to 444V.   It is connected to an identical capacitor.  What is the new voltage on each?  They are then disconnected.  What is the final voltage on each.

    x2: A Leyden Jar of capacitance C is connect to a battery with potential V.  It is disconnected from the battery, and then connected to another jar of capacitance 3C.  a. What charge is on each jar?  b. What potential is on each jar?

    x3: A variable capacitor is charged with a given potential.  a. What is this initial charge?  the capacitance is then quadrupled.  b. What is the new charge?  c. what is the new potential?

    Thursday and Friday:   CONFERENCES

    HW due next Monday: Capacitor Lab is due.   

    Goals for this week

    • Show that electrical current, I, is an outgrowth of charge and time.  
    • Understand the parallel of electrical flow and water flow
    •   Be able to describe that V is the potential for work, and I (current) represents real energy expenditure
    •    Show ability to use I = V/R
  • MONDAY: NO SCHOOL

    TUESDAY

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    THURSDAY

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