Physics 240 Assignments - Spring 2015

Mon. 1/26

The following instructions pertain only to students already registered for Physics 240 at Grossmont College.  Registering with WileyPlus does not give you permission to take the class.  It is something you do after you have enrolled in the class at Grossmont College!

The first thing you need to do is to register for the course with WileyPlus.  You do that by going to the site http://edugen.wileyplus.com/edugen/class/cls436759/ which is specific to Physics 240, not to sections of Physics 140.  If you cannot easily figure out what to do, you can go to Wiley Student Resources and Support for some help. 

Assignments will be listed on the date due, not on the date assigned! Other announcements will be listed as they occur.

We will be covering the first two chapters of the semester merged together.  The order will be approximately as follows:

18-1 → 18-4 (18-3 in lab)
19-1→ 19-4 (postponing work done by an ideal gas until 18-5; we are skipping 19-5 & 19-6)
18-5 (we are skipping 18-6; work done by an ideal gas in the second part of 19-2 will be covered here)
19-7→ 19-9

Thu. 1/29

Thermal Expansion lab.  If you need a copy, you can print it here.

Wear closed toed shoes.

Bring your lab notebook to record your data. 

Bring a copy of the lab or your lab manual.

Be there at 8 A.M.

Read the following sections from your lab manual prior to lab:

• Introduction to Measurements and Uncertainty
• Significant Figures and Uncertainty
  
• Guidelines for Laboratory Experiments and Notebooks
  

• Laboratory Reports

If you don't have the manual, you can print them out here.

I find the following website useful for constants:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/ttab.html

Thu. 2/5

Determination of absolute zero.  As always, you will need your lab notebook to take data.    BE ON TIME!

Mon. 2/9

 The first homework is assigned and is due on this date.

Once the first homework is assigned, you will find it when you go to the WileyPlus website.  All problems are to be done online.   They do not all have the same format; some are numerical, while others are multiple choice.   I recommend printing them out and thinking/working them out offline.  Only when you have finished working them out on paper should you enter the answers. 

Homework comments:

1) Most of the homework problems ask for a specific number of significant figures.  I have found that you get the answer closest to the book's answer if you do NOT round off intermediate steps to the correct number of sig. figs.  Only round off the final answer.

2) You can enter numbers in scientific notation if you need to do so to get the sig. figs. in correctly. An acceptable format is #.##e# (e.g. 1.23e4)

3) The book is not sticking to just one set of units here. They are using cal and Cal (what's the difference?) and putting specific heat in terms of J, kJ, g, and kg.  Be careful.

4) I don't think the answers are completely consistent on where to use Cº instead of ºC.  So, don't wait until the last try to enter your units!

Thu. 2/12

The Mass-Lifter Heat Engine lab.   You should bring a thumb drive to take away your data and a mouse to make it easier to use the computer.   You can bring your own laptop; if you have LoggerPro, it might be useful.

Remember, you have to show up on time to get full credit. 

The Temperature of Absolute Zero lab should be due here but it will be postponed if your last lab has not been returned.

Mon. 2/16

The second homework assignment is assigned and is due on this date!  The 25% penalty for late work WILL be assessed!  That penalty is assigned problem-by-problem and does not apply to the entire assignment if only some of the questions are late. 

Thu. 2/19

Start time: 8:30 A.M.

Lecture in Lab.  We will start with a QUIZ on equilibrium temperature of samples of H₂O.  This could be in any state, solid (ice), liquid, or gas (steam).  Given various quantities, you might have to compute equilibrium temperature, initial temperature, or mass.

Values for the specific heats of water, ice, and steam plus heats of fusion and vaporization will be provided as needed.

Temperature of absolute zero lab finally due.

Mon. 2/23

The third homework assignment is assigned and is due on this date!  Remember, the 25% penalty for late work WILL be assessed!  That penalty is assigned problem-by-problem and does not apply to the entire assignment if only some of the questions are late. 

Wed. 2/25

We are starting chapter 21 here.

The computer room is now open Monday, Tuesday, Wednesday, and Thursday.  See the schedule here.    During most of this time, tutors knowledgeable in this material will be available.  

Thu. 2/26

We will start with a quiz, so don't be late!.  The quiz will be on gas laws and the first law of thermodynamics. You will have to calculate internal energy changes, heat, and work for one or more of the four processes we have used: constant volume, isobaric, isothermal, and adiabatic.  The quiz will start promptly and last for no more than 30m.   If you are late, you will not have the full time.  If you miss it, there are no makeups.  I will give you the thermodynamics formula sheet shown on the main web page.  The quiz will not involve a heat-engine cycle.  On the test the following week, you will have to calculate the efficiency of a full cycle.

The heat engine lab is due here.  You should get it done and turn it in.  Remember to follow exactly the instructions for organizing the calculations.  If you have trouble completing the lab, you can ask questions and I will try to assist you.  No explanation of physical principles is necessary for this lab.  Discuss the topics mentioned in the "Conclusions" section of the write-up.

Don't forget you need a graph for each cycle you turn in - you need to turn in two with different temperature ranges.  All of the work terms need to be calculated with the trapezoid rule.  Also, follow the instructions on how to organize your writeup!

Introductory Circuits lab.  This is a "fill-in-the-blanks" lab on a topic we have not covered yet.  So, BRING YOUR LAB MANUAL!

Mon. 3/2

Wed. 3/4

Review for exam on chapters 18, 19, and 20 will take place on Monday.  The problems are posted here. There are only two problems, but they have multiple parts, so they give pretty good coverage of what you need. 

The solutions WILL BE posted in WileyPlus (written with Work_on rather than Work_by).  

The test will be on Thursday during the lab period.

Thu. 3/5

Test on chapters 18, 19, and 20, starting at 8:10 A.M.

Here is the formula sheet we will use.  You will be given one with the test.

Thu. 3/12

The fifth homework is assigned and is due here.

Basic Electrostatics lab.  This is a long fill-in-the-blanks lab.  You MUST bring your lab manual so that you have the blanks to fill in!

This would be a good time to review projectile motion.

Basic Electrostatics lab due.  Answer all the questions carefully on the pages of the lab writeup.  Do not do a separate lab report. Only turn in pages with your results on them, not pages containing only instructions.   If you did not get good results, also discuss what should have happened.

Wednesday, 4/1  The seventh homework is assigned and due here.  Although some of the problems involving extended charges can be done by "cribbing" equations from the chapter,
you will learn more if you work through the integrals yourselves. 

Thursday, 4/2  Electric Fields and Potentials lab

                                Van de Graaff lab due.

Wed. 4/8

The eighth  homework assignment is assigned and due here.  Most of this is chapter 23, but one problem is from chapter 22.  In symbolic equations, use epsilon sub 0, not k.

Thu. 4/9

Capacitor lab.  We will measure the capacitance of a capacitor made with notebook paper stuffed inside a textbook. 

Electric Fields and Potentials lab.  If you turn it in on time, I will get it back before the test! 

Remember, you don't have to do a full writeup.  Draw the equipotential lines based on the measurements and sketch in the field lines.  Do this for each drawing made by your group, your own and copies of the other ones. YOU NEED THREE!  Make sure to indicate which map you made.   Then use the equipotential lines to calculate field strengths on ONE of the drawings as described in the writeup and answer the questions.  This is good practice for part of the test!  Remember you need arrows and an indication of which conductor is positive and which is negative. Use the electrostatics 3-D program on the computer lab computers (or any equivalent program you find) to try to model your arrangement as closely as possible.  Some instructions for that program are given in the lab writeup.

Remember to print out your paper so that you have dark lines on a light background.  Or, you can trace it.  If you cannot do that, you must write with a white or yellow pencil.

Wed. 4/15

The 9th homework assignment is assigned and due here. Two of the problems are "extra credit"  The assignment will probably be "due" at 5 P.M. so that the answers can be posted.

Review for the test.

Here are the review problems.  Make sure you read the introductory paragraph  of the review problems for more information about the test. Several of the review problems are harder than any test problem will be.    A scanned version of the handwritten answers IS posted inside of WileyPlus.

The formula sheet is here.

Remember, if you turn in the Fields and potentials lab on time, I will get it back to you before the test. 

Test, beginning about 8:10 A.M. Chapters 21, 22, 23, and 24.  This covers fields and potential of point and distributed charges. Gauss's law.

Here are some problems that will certainly be on the test: (not necessarily in this order):
1) electric field and potential of two point charges (NOT calculated just on the axis of a dipole).
2) electric field inside and outside a charged insulating sphere or long cylinder.  This will have a non-uniform (but symmetric) charge distribution.
3) motion of a charged particle in an electric field ("projectile" type motion).
4) derivation of the potential from the field or the reverse
5) simple torque or mechanics problem (like the homework)
6) conservation of  energy (kinetic and potential)
7) field of a charged rod or semicircle

Electric fields lab due!  If you turn in the electric fields and potentials lab by the start of the test, it will still be considered on time.

The tenth homework is assigned and is due here. 

Beginning at 8:30 we will have a lecture in lab.  The lecture will complete circuits with a resistor and capacitor and then begin the coverage of magnetic fields.

In order to work with magnetic fields, you need to know how to calculate the vector cross product using components in 3 dimensions.  If you don't remember how to do this, you can find the math in chapter 3 of Halliday, Resnick, and Walker.   You can also find it in chapter 10 of Tipler and Mosca.  There is a copy on reserve in the library.  While you're at it, review torques in three dimensions (hint: electric motors).  Also, go way back and review circular motion and centripetal acceleration (charged particles move in circles or spirals in a magnetic field.)

After approximately 1.5 hours of lecture, you will be allowed to redo a portion of the test.  The same formula sheet will be provided.  You may redo a maximum of three problems worth a maximum of 15 points.  For the purpose of this makeup test, problems 6a and 6b count as separate problems, 5 points each.  You must choose which three problems to do.  The instructor will NOT select the best three if you do more than three.

The difference between the new problems and the old problems will be added to your test.  In order to get the additional score, you must turn in both the new version of the test and your old version.  Both will be returned to you.

The Notebook Paper Capacitor lab due.  Remember, it is divided into two parts that do not depend on each other. 

Torque on a current loop lab.

The eleventh homework is assigned and is due here.  (It was originally due on 4/30.)

The Torque on a current loop lab is due here.

The Charge-to-Mass Ratio of the Electron lab.

The twelfth homework is assigned and is due here.

Test: chapters 25, 26, 27, and 28 .  We'll start at 8:00 or 8:10 A.M. TBD.

Here are some review problems.   There will NOT be an in-class review session.  Work these problems and discuss any issues during office hours.  The scanned answers HAVE BEEN placed in WileyPlus.

The formula sheet is here.  Look it over for mistakes or (what you think are) omissions.  You should look it over before the test as some formulae are given in condensed form, and you should make sure you know what all the symbols mean.  For example, the charge on a capacitor in an RC circuit is given as a function of time.  How would you derive the current and voltage as functions of time? 

The test will include a number of problems.  Problems worth 5 or more points will probably be as follows, but there could always be a problem on anything we covered:

1) a charged particle moving in a magnetic field: force, path, radius, pitch, period, frequency
2) force on a current carrying wire made of one or more straight line segments in a magnetic field.
3) capacitors in series and/or parallel
4) a network of multiple resistors in series and parallel with one battery
5) a network of multiple resistors with two or more batteries (Kirchoff's node and loop rules required).
6) torque on a current loop

Other problems which could be worth lesser numbers of points could be as follows:
1) resistivity and resistance
2) charging or discharging an RC circuit.

Short answer problems could be on any topic.

Check back to see if there are changes.

The 13th homework assignment is assigned and is due on this date. This gives you a full week after the test, but you really shouldn't leave it until this late! Why not?  There will be two more homework assignments, numbers 14 and 15.  Assignment 15 will be extra credit.  Note that although the assignment is extra credit, the material on assignment 15 will be on the final.  These assignments must be due before the final and cannot be postponed, so work on assignment 13 before the last possible minute and leave time for 14 and 15.

The charge-to-mass ratio of the electron is due here.

Oscilloscope lab.  LC and RC circuit time constants.  There will be no writeup to turn in.  BRING YOUR LAB MANUAL.

The 14th homework IS assigned and due on this date.  This is on chapter 30.  It will NOT be postponed.  Although some problems can be answered by taking formulae from the book, it is usually better practice to work the problems from scratch, as if they were on a test.  There will also be an extra credit homework assignment due the afternoon before the final.  Note, although that assignment will be extra credit, the material will be on the final.

The computer room will be open as follows:

Tuesday :    12:00 - 3:30 P.M.
Wednesday: 9:00 - 11:15 A.M. and 1:00 - 3:00 P.M.
Thursday:     10:30 A.M. - 2:00 P.M.

At this time I have no planned office hours.  However, you can call my office or email me to see if I am there Tuesday afternoon.

The 15th (optional) homework assignment is posted and  "due" on this date at 5 P.M..  The points for this assignment will be treated differently from the other assignments; they will only go in the numerator, not the denominator, when the homework percentage is computed.  Although the homework will be optional, the material will be covered on the final. 

We will have a review for the test in the lab from 9:15 A.M. until 10:45 A.M. 

The final will cover chapters 29 and 30.  Remember, although the final concentrates on material from those chapters, you may be expected to use knowledge from prior chapters (or semesters!) during the test.     Physics is cumulative. 

Here is a reminder of the main topics we have covered. 

fields of  loops
fields of single and multiple long wires
force between two wires (not on the formula sheet - hint!)
Ampere's law
self inductance and mutual inductance
inductors in circuits with resistors (and capacitors in circuits with resistors, but not capacitors and inductors together in a circuit)
Faraday's law in a variety of situations (such as the sliding rod on a rail or electric generator)

Here are some review problems.  Remember that these are primarily reminders of the topics we have covered.  Do not expect a one-to-one correspondence between review problems and test problems. Written solutions are posted as a document in WileyPlus. 

Here is the formula sheet for the final.  Look it over to make sure you understand what each equation refers to.

All labs that have been turned in will be graded by the final.  No labs will be accepted after the start of the final.

If you turn in the e/m lab at the review session on Wednesday, there will be a 1 point penalty.  If you turn the e/m lab after that, there will be a two point penalty.

Any labs other than the e/m lab turned in by the review session on Wednesday will receive a two point penalty.  Any labs other than the e/m lab turned in at the final will receive three points, regardless of how much (or how little) has been done.  So, you can bring your data sheets for any lab which you have not turned in and receive three points.

Labs subject to these scoring rules must be turned in to me personally or put under my office door prior to the final.  My mailbox in the administration area does NOT count.

The final will be Thursday, May 28, from the usual 8 - 11 A.M..  The official time is 7:15-9:15 A.M.  If you want to take the test during that time, you must let me know in advance.  But remember, if you get the official start time, you also get the official end time (9:15 A.M.)  

At some point I will post the last time to do homework for credit.  It will be after the final.