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Is it normal to not understand any homework questions?

  1. Apr 5, 2012 #1
    So I'm in my last semester at my local community college and I'm taking Modern Physics. The class is cool and all, but the material is very hard to grasp. Furthermore the homework questions, (to me), are nearly impossible to complete. It takes me close to thirty minutes just to understand what the problem is asking, and this is usually after asking my professor to explain it to me. Then it takes anywhere from an hour to three to attempt to solve it, which usually ends in failure because I have no idea what to do. After three hours on one problem I get so sick of it I pretty much have my professor walk me through it step by step so I can get the answer. I still don't understand how that was the answer but I've asked too much already to have her explain it again. I've never had this problem in physics before and it's bothering me to think that if i can't handle this class I have no hope to handle any other classes once I transfer. So I'm basically asking this a normal process when it comes to dealing with "higher level" physic courses.

  2. jcsd
  3. Apr 5, 2012 #2
    I'm currently taking Quantum Mechanics and the general consensus among my peers is that it usually takes anywhere between 1 to 3 hours to do each homework problem. I'd say it really depends upon the course and professor, and the level of rigor of the homework problems. Would I say it is normal to not understand homework problems? I'd be surprised if anybody on this forum had never experienced difficulty understanding a homework problem.
  4. Apr 5, 2012 #3
    I took Modern Physics last semester. We covered Special Relativity, some Statistical Mechanics, introductory Quantum Mechanics, and some Particle Physics. I,myself, had issues where it would take me a while to figure out what exactly the question was asking.

    In general, the steps I took that helped me were:

    1) Read the chapter (duh!), but also write down any relevant equations given.
    2) Read the question you're doing. What variables are they giving you? What variable do you need to find?
    3) See if there is any immediate relationship between the variables you know and the equations given. Is there a consistent mathematical relationship?
    4) If not, reread the relevant section. A lot of textbooks make this easy by grouping questions by section. However, you may need to go by section titles instead.
    5)Try solving with your new found information. Does the answer make sense? In non-classical physics this may be harder to figure out. In this case, go over your steps and see if your reasoning is consistent.
    6) If that fails, ask your professor about your steps, or seek outside sources.

    I hope this helps.
    Last edited: Apr 5, 2012
  5. Apr 5, 2012 #4


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    For example, here. :wink:

    Conceptual questions for a course like this probably belong mostly in the Quantum Physics or Special & General Relativity forums. For help with specific exercises or homework problems, probably the Advanced Physics sub-forum of Homework & Coursework Questions.
  6. Apr 5, 2012 #5


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    I'd also suggest getting another text as a companion textbook, possibly from the library. There may be a text out there or a website even that explains the subject in a way that clicks for you.
  7. Apr 5, 2012 #6
    Can you post an example of a question that took a half hour to understand what was being asked?
  8. Apr 5, 2012 #7
    In comparison, how did you do in calculus based Physics II -- electromagnetism? How long did the homework problems take?
  9. Apr 5, 2012 #8


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    I'm having the exact same problem of the OP with the same course (Modern Physics II in fact, dealing with molecules and complex atoms rather than 1 electron atoms which was a part of Modern Physics I).
    I have like 15 problems to solve before the end of the next week, yet I cannot start a single one. I asked the solution to another student (he studies chemistry too) of the first exercise; it's 5 pages long and I hardly understand what's going on. I photocopied it, if I have time I might try to solve the problem alone, but it's not a given.
    Furthermore I also lack books (there's only 1 copy of Brehm's book in our library and it's never available). Our professor does not follow a particular book, he even refers to papers from time to time. Yes the course is hard in itself and so are the exercises. The lack of ressources, or the lack of a particular book is an uterly huge pain to me.
  10. Apr 5, 2012 #9
    I'm curious what book, if any, the OP is using for this course. Next semester, I'm taking Modern Physics and like fluidistic the course does not stay with a particular book. The syllabus recommends 2-4 chapters from about 10 books, ranging from math methods, relativity, quantum, and waves. On the webpage, they have a couple pdf's of lecture notes and then that's about it.

    Right now, I'm taking a course that is using a similar method to that class and it's very frustrating for me since I'm methodical when I learn something. Modern physics seems like it's a wide range of topics thrown into one class.
  11. Apr 5, 2012 #10
    Don't get discouraged after 3 hours. I've easily spent more time on problems before, regularly.


    1. As soon as the homework is available - read and attempt it! You don't need to plan on completing it the first day, just start thinking about the problems. This gives you some time for the problems to sink in. (Sometimes when I do this, a solution will just "pop" into my head in the middle of the week, without me actually thinking too aggressively about the problem.)

    2. Work with other students! Don't copy answers, but work with them. Trying to understand others solutions and trying to explain your own is a very valuable learning experience. Another thing you'll realize is that many other students are struggling just as hard as you! This is expected.

    3. Work through your book's example problems. Most examples are picked because they are important! Understand each step completely, before moving on.

    4. As suggested already, get a few more similar textbooks on the subject from the library. Sometimes having a concept worded slightly differently can make a big difference.
  12. Apr 12, 2012 #11
    I am not a physics student, so I can't give specific advice. But my friend and I were totaling up how long it usually takes us to do our math homework, and depending on the class it's not unusual for each problem to take half an hour or more. We had one bad day where we sat in the computer lab for three hours and got two problems finished and gave up halfway through a third one. Three hours for one problem sounds a bit much, but maybe not if they're intense/abstract questions. One of my professors said in grad school he used to get one problem a week--and the problem would take a whole week to solve. When I was taking linear algebra I pretty much had my professor or a more advanced friend walking me through a lot of the problems. It happens.
  13. Apr 13, 2012 #12
    Don't be disheartened if you can't figure out questions after trying for a long time. I took a upper-division logic class on Godel's Incompleteness Theorems, Model Theory, etc. and it took me a few hours to understand what the questions on the assignments were EVEN ASKING. I spent over 100 hours on one assignment that had 6 questions, so don't think you have it bad!

    Try to keep with the question and have resilience, just try a bunch of different approaching and trying to write something down! I'd find that I could sit there and stare at the question for 30 minutes and make no progress, but if I just start to write down definitions and start writing SOMETHING I would make progress. So, if you are ever stuck, just try writing down something and it should come. Maybe that might help!
  14. Apr 13, 2012 #13


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    The point in the quote above have been crucial for me. I want to stress its importance, so here are a few remarks:

    I used to have a strong aversion to working with others; I often felt as if it made things more confusing and that I ended up worse-off than when I started. However, I've learned to pick study partners more effectively, and whenever something comes up I suspect is erroneous and/or I don't understand, I question it: Why doesn't that make sense? Or even, Why DOES it make sense?. This can be time consuming, but I don't see how one can fully understand complex concepts without asking these types of questions.

    Another idea:

    Something I'll occasionally ask a professor: "How long, on average, should I be spending on the problems in this set?" Don't bang your head against a wall any longer than you have to. Sometimes you just need to admit you don't know how to do something and get help, and try to avoid blindly guessing. If you have an educated guess, by all means go with it, but don't start entertaining random ideas that are a product of panic or frustration (it can cause a lot of confusion and is very time consuming). Have clear, logical reasons behind your methods.

    There is a balance that needs to be maintained. Struggling through a problem is certainly part of learning, but only to a certain point. Your professor should know what is reasonable and what is not.

    Take the professor's time estimate and stick to it; get as far as you can and then go to office hours with specific questions.
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