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### Griffiths QM Solutions Manual

Posted: **Sun Jan 20, 2008 9:44 pm**

by **theodiggers**

I love Griffiths books, but I'm using them for self study. I was sly enough to get my hands on a copy of the intro to E&M solutions manual and have thus conquored 1-7, 12 of E&M. It is the biggest shame in science that we don't have access to solutions manuals. they were the most amazing thing about Wade's organic and a properly used solutions manual, you know, kicking yourself on a problem for 40 minutes, then looking up only the next step, and then redoing it and figuring out why they did it like that, well man thats how you learn without a professor and without coughing up tens of thousands of dollars! That the academy and thus humanity is shackled by industry in this way is really sad. So anyway, who's got that copy of the Quantum solutions!

### Re: Griffiths QM Solutions Manual

Posted: **Sat Apr 12, 2008 12:41 pm**

by **Jimbo**

I too do a lot of self-study, and I agree with you about solns manual's pedagogical efficacy.

There is tho, a primary reason they are not available to the gen public:

CHEATING !

I taught classical mechanics at one of the universities in Oregon out of Marion.

Discovered a mid-term xam answer which was verbatim copied from the solns manual.

Incredulously, I found out there was a black market copy available online.

Needless to say, I switched to another text.

### Re: Griffiths QM Solutions Manual

Posted: **Sat Apr 12, 2008 1:11 pm**

by **will**

Why would you give your students a midterm exam where you copied the question verbatim out of the book?

### Re: Griffiths QM Solutions Manual

Posted: **Sat Apr 12, 2008 1:18 pm**

by **twistor**

Because that's what teachers do when they're not smart enough to come up with their own questions.

### Re: Griffiths QM Solutions Manual

Posted: **Sun Apr 13, 2008 4:41 pm**

by **doom**

Yeah, he should've gotten an M.Sc. in engineering instead.

### Re: Griffiths QM Solutions Manual

Posted: **Mon Apr 14, 2008 4:55 am**

by **quizivex**

Yeah it's hard to debate whether the solution manuals should be available to everyone or not... Obviously, if cheating were too easy, it would ruin courses or make them rely entirely on midterms. On the other hand, seeing worked problems and examples is enormously helpful for students. Most textbooks I've looked at, I've been just crying out for more examples and illustrations of the concepts (except for gen physics books, which I've been mostly satisfied with). Having majored in math too, I can objectively compare the two fields and say the math textbooks are far more lucid and illustrative than the physics ones. Everything is built from the ground up. The math books are teeming with worked examples ironing out the nuances of the material, and the problems are thought provoking, manageable, instructive extentions of the chapters. But in physics, the theory is often not derived, either since it's too complicated or "beyond the scope of the book." They whip out mathematical methods that aren't even covered in my math classes. Case in point: Thornton-Marion's half-assed chapter 6 on the calculus of variations. The end of chapter problems are a huge leap from the chapter itself... for ex. the second half of Griffith's E&M. Random approximations are thrown in here and there. etc... Another reason I needed the GRE was to convince myself that I really can understand this stuff and it's and not necessarily that I should switch to math...

I'm glad I got a hold of Griffith's E&M and TM Mechanics solution manuals since I hope to try to hone my physics problem solving skills this summer. Having quantum too would be sweet though...

I think it'd be best if the solutions manuals for the "most popular" books were accessable to everyone, and that profs teaching courses would do a little extra work to construct problem sets from sources other than the book used in class.

### Re: Griffiths QM Solutions Manual

Posted: **Mon Apr 14, 2008 8:47 am**

by **will**

Now, to be fair to Griffiths, he covers a lot of difficult concepts only in problems to keep his book thin. I guess he knows students can read and maybe uses his class time more wisely. It makes self-study problematic, sure, but I always thought that was why we had teachers.

... But my E&M professor just got so upset when he found out that some students were plagiarizing homework solutions from the manual that he just started plagiarizing his homework questions from other sources instead. Hm.

### Re: Griffiths QM Solutions Manual

Posted: **Mon Apr 14, 2008 6:33 pm**

by **grae313**

quizivex wrote:I think it'd be best if the solutions manuals for the "most popular" books were accessable to everyone, and that profs teaching courses would do a little extra work to construct problem sets from sources other than the book used in class.

Or, go ahead and assign homework from the book, just don't let homework count for any points. Let the whole grade be determined by the exams and let the professor write their own exam problems. Problem solved. The students who copy will not be prepared for the exams.

### Re: Griffiths QM Solutions Manual

Posted: **Mon Apr 14, 2008 7:17 pm**

by **excel**

grae313 wrote:quizivex wrote:I think it'd be best if the solutions manuals for the "most popular" books were accessable to everyone, and that profs teaching courses would do a little extra work to construct problem sets from sources other than the book used in class.

Or, go ahead and assign homework from the book, just don't let homework count for any points. Let the whole grade be determined by the exams and let the professor write their own exam problems. Problem solved. The students who copy will not be prepared for the exams.

That may be a bit unpopular with the profs because then the book will either make the prof work harder or change the profs' favored grading scheme. I doubt the publisher will actually implement a policy that will reduce the book's popularity with the profs; most students buy a text because the prof assigns it for the class.

### Re: Griffiths QM Solutions Manual

Posted: **Mon Apr 14, 2008 8:32 pm**

by **will**

I was under the impression that Griffith's E&M enjoyed nearly the same monopoly status among undergrads that Jackson holds over grad students; this may be incorrect, but i do know it's a pretty popular text and also that the solutions manual is pretty readily available, which hasn't seemed to decrease the text's popularity.

Then again, it also doesn't get professors to write their own questions so maybe it's a moot point.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:02 am**

by **Helio**

Griffith's E&M has a monopoly to say the least. I found another book.. Ohanian Classical Electrodynamics. It is a good book, but in CGS, I doubt anybody wants to deal with stat-volts anymore.

I use the solutions manual for Griffith's to understand the concepts. i can't live with the half-assed examples, or lack there of, he gives. one of my profs taught straight out of the book.. nearly verbatim, but after that class i had my electrostatics down. It was grueling semester, but i understood it. in part due to the solutions manual. i worked through all the problems... yes all... the ones i got wrong i could reference.

in electrodynamics the book is ***, in all honesty. it seems like stuff comes out of the blue and most of the questions seems plug and chuck. It might just be the problem having two extremes teach the two parts of the course. Statics by a string theorists who lives and breaths HEP and dynamics by condensed matter experimentalist. One understood the concept of homework that is supposed to take time and tests that were straight forward for the most part, the other making homework an utter joke and tests that make you ask yourself if you were taking a course in english poetry based on Maxwell Equations.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:31 am**

by **dlenmn**

I thought that Griffith's books (well, I've only used the E&M and QM) had pretty good worked examples and explained the concepts quite clearly. Yeah, many of the problems differ from the examples, but that's what you want! A lot of math text books with many worked examples give you one example, then a bazillion homework problems which are essentially the same, just with a few values changed. I don't think that's the way to learn anything except plug and chug. Having exercises that differ from the examples makes you really learn the concepts. Still, I can see how that (combined with his choice to stick so many interesting points in the problems) makes it hard to do self study. A good prof who can help you to the answer is much more useful than the solutions manual, but I understand that's not always available, so the solution manual may be the next best thing.

On a different subject, I think it's a poor idea to make exams the only thing which counts for grades. Actual physics work is a lot more like a problem set than an exam -- you work with other people, you have references on hand, there's not a 3 hour time limit, etc. -- and you want to teach people how to do good physics work. Making problem sets not count in the grade discourages people from doing them, and is thus counterproductive. (I guess you could argue that by making problem sets not count, you are motivating people to learn to motivate themselves, but I don't think that's the answer. Some initial motivation might be needed to get the ball rolling. Also, It's a lot easier to motivate yourself for a research project you've chosen than for a class you have to take, so there's no point in setting up an artificially high motivation barrier that discourages people who might otherwise get over the lower but more real and important motivation barrier).

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:51 am**

by **Helio**

the whole problem i had with it was that the examples seemed overly obvious. esp, in chapter 3 and 4 i was like... yeah so what about other geometries. in general, it does not matter we got work with what we are given

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:53 am**

by **excel**

Well, grading HWs creates jobs for graders/ TA!

One advantage of HWs is that profs can set interesting and challenging problems on HW that would be inappropriate on a timed exam.

I think a fundamental question is:

Is HW merely a form of preparation? Or, is HW also meant to examine the student's understanding?

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:58 am**

by **Helio**

it should be the examine the understanding.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 1:04 am**

by **excel**

If HW is intended for a prof to examine a student's understanding, then it does have to be graded and factored into the final grade...I can see no other way out.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 1:47 am**

by **Helio**

i somehow doubt professors assign homework for kicks

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 10:16 am**

by **twistor**

None of the above. Homework should be treated as a feedback mechanism where students can evaluate errors in their own thinking and correct them. It is not appropriate to examine a students understanding of the material through homework assignments.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 10:50 am**

by **dlenmn**

twistor wrote:It is not appropriate to examine a students understanding of the material through homework assignments.

Oh. Well if you say so, then it is assuredly true twist!

Is not a "mechanism where students can evaluate errors in their own thinking" a thing that "examine[s] a students understanding of the material"?

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:03 pm**

by **twistor**

Sure, but they should not be evaluated on it before they have an opportunity to master it.

### Re: Griffiths QM Solutions Manual

Posted: **Thu Apr 17, 2008 12:57 pm**

by **marten**

Griffith's E&M has a monopoly to say the least. I found another book.. Ohanian Classical Electrodynamics. It is a good book, but in CGS, I doubt anybody wants to deal with stat-volts anymore.

What about Reitz, Milford, and Christy, Foundations of Electromagnetic Theory? I don't see this book mentioned very often on this forum, but I've seen several universities mention this text as expected undergrad prep. I thought it was a pretty good text, although I took that class 9 years ago...

Marten