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Physics: E&M

  1. May 15, 2007 #1
    Do you need to be very good at introductory mechanics to do well in introductory E&M? Or can you still do good in E&M (get an A) if you are not very good at introductory mechanics? To prepare for intro E&M should I do (A) review intro mechanics or (B) start studying E&M from a book like serway or halliday/resnick. My goal is to get an A in intro E&M. Also do you have to be naturally good at physics (also error analysis) to major in it?
    Last edited: May 15, 2007
  2. jcsd
  3. May 15, 2007 #2


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    Homework Helper
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    What is your problem with introductory mechanics. One thing you should make sure your good with from mechanics is all the vector concepts. (How to use them, How to add/multiply them.) Vectors become just as if not more important in E&M as compared to Mechanics.
  4. May 15, 2007 #3
    Yeah I am good with the vector concepts. But how about all of the other concepts (thermodynamics, momentum, energy, gravitational fields, etc..). If I am rusty in these areas, should I brush up. Or can I start studying E&M?
  5. May 15, 2007 #4


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    Just start in on E&M. You can go back and review anything that comes up later. Don't sweat it at this point -- dive in and study well, and you will enjoy E&M. It was one of my favorite parts of school (and now work).
  6. May 15, 2007 #5
    If you’re basically talking about calc based physics 2, you will need to know a bit more calculus then you did in physics 1, but not much more.

    If you’re talking about a more advanced undergrad E&M course, you will need to remember a lot of stuff from multivariable calculus like vectors and triple integrals in Cartesian, spherical, and cylindrical coordinates. Also, gradients and curls, dot products, cross products, and equations of planes, lines, and space curves. Review Gausses law, Maxwell’s equations, and coulombs law.

    (The following goes for both physics 2 and a real UG E&M course.)
    Other then that, if your worried about getting an A, find out what book the class uses and start working your way through the chapters, don't move to a new chapter until you can do most of the EOC problems.

    Get ahead and stay ahead. When it comes time for the tests, make sure you have done every homework problem at least 3 times, start to finish. Don't refer back to your older work unless you’re really stuck, 5 mins does not constitute being stuck. If you get the chance, look over other peoples solutions and if they do not match your own, make sure you understand why their solutions were also valid.

    When I get a problem wrong in a problem solving type of class, the last thing I'm interested in is the real solution. The thing I want to know is, WHY didn't MY solution work? What was wrong with my thinking or understanding that prevented me from getting the right answer? Once you can answer these 2 questions, you won't need the actual solution, you will already know how to find it:approve: .
  7. May 16, 2007 #6
    EM really felt different than mechanics to me. that said, you should maybe get comfortable with the gravitational field stuff from mechanics, because electrostatics borrows quite a bit from that.

    on the whole, i really liked EM much more than mechanics.
  8. May 16, 2007 #7
    For what it's worth, E&M is my strongest subject, and Classical Mechanics is consistently my weakest. I second what Berkeman said.
  9. May 16, 2007 #8
    very few problems in intro E&M use concepts from mechanics. It uses dot product and cross product, but you learn those from calc III. I forgot quite alot of the concepts from mechanics, but am currently sailing thru E&M.
  10. May 17, 2007 #9
    To get a fair idea of what EM is, you should have a look at "Introduction to Electrodynamics" by DJ Griffiths. The first chapter is on Vector Analysis and some other mathematical preliminaries, and if you read from Resnick/Halliday or any other textbook of comparable level, you will not need anything beyond the mathematical preliminaries in Griffiths (in fact possibly less). While Classical Mechanics may not be immediately important in your study of EM Theory, if you go on to study more advanced EM theory, then you will definitely need to know CM.
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