About Homework (FALL 2008)


Weekly homework assignments (See HWAssignments for details and due dates, and HOMEWORK for the texts of the weekly assignments and their solutions) are due in class weekly, normally on Wednesday (except for schedule adjustments to keep them aligned with lecture material).  They consist of ``Conceptual Questions'' (designated by CQ) and ``Exercises'' (designated by ``Ex''). 


For Physics 117, HW is a necessary learning experience: in physics, the ability to quantify one’s knowledge in the form of computations is essential. The HW exercises quantify the physics you have learned. In addition, once the answer to a problem is obtained as an algebraic expression (as it should always be obtained before you insert, at the last stage, the relevant values of the numerical parameters to obtain your numerical result), it becomes a tool for generating physical intuition by considering how the result  might change for other values of the parameters (and especially extremely large or extremely small values, where phenomena often exhibit especially clear and simple behavior), or by asking oneself “what if?” questions: What if x had been given and a, b, or c, required, instead of the other way around? Exploited in this way, HW problems can qualitatively enhance one’s physical intuition, which helps immensely in coping efficiently with the course exams, which attempt to reward clear intuitive understanding.   


Check Your Own Homework


We shall generally assign odd numbered HW problems, so that you can readily check your answers which the text provides in its Appendix A. (Be aware that printed textbook answers are wrong with surprising frequency. If you think an answer you obtained is correct and the text’s is wrong, check further….you may very well be right.)


We shall post the solutions to the HW problems in the glass case outside the lecture room , and on our 117 course website a week or more before the assignment is due. (Click HOMEWORK or Recent Announcements to find a link to each HW solution set posted.) You are encouraged to work ahead of the HW due dates: This allows you to identify sticking points early and clarify them when they arise in lecture. It also gives you the opportunity to set your work aside and then to return to it for a review before it has to be submitted. 


If at first a problem baffles you, re-check the text to see what you missed. Then look at the full solution to see whether that helps to clarify things. If it does not, you need to talk to someone about it.  Look for help. Other students are often the most immediately available (e.g. in the hall before lecture) source of help, but do not hesitate to ask the TA or the professor, during their regular published office hours or by appointment at other times. (Both announce and keep office hours specifically to invite questions and discussion of your individual difficulties.) Also, ask for help sooner rather than later. HW confusion, if left unsettled, undercuts the basis for the next stage of learning and generates more confusion. When you are finished your homework, check your solutions against those posted on the website to see whether any fine point eluded you.


HW Grading


The homework will be graded and returned each week. The grading, however, will be only partial, due to the limited TA time available for this task. Generally we shall grade one problem fully in each set (generally 10 problems) for 3 points and add an additional point for each of the other problems for which an apparent good faith effort at solution was made. Thus each 10 problem HW set will typically carry a maximum grade of 1*3+9*1=12. Note that the answer alone is not a good faith effort at a solution. That much is usually given by the text book. Even if the problem seems trivial, show us that you understand where the answer comes from.


The task of the HW is to learn how to do the problems, and you should use all of the means available to you to do so. But in the end, having learned what you needed to know, you should write your own HW solutions from your own knowledge. Clearly there is no way to prevent a student’s copying posted HW solutions and handing them in as his own. But we believe that is a self-destructive strategy, because the skills left unacquired thereby will drag down one’s test scores disproportionately. Furthermore, if a comparison of a submitted HW set and the posted solutions would lead a reasonable person to conclude that the solutions were simply copied, then that HW set will received the appropriate grade, zero.


On the due day, place your homework solutions in the folder for your lab section at the front of the lecture room just before or just after class (-not during class time).  Please staple the pages together (using the stapler beside the folders trays, if necessary) and put your name and lab time (e.g. "Thu 4PM") on every page. 


Homework not submitted in class will be considered on time if placed under the door to Physics Room 2109 on the due date, i.e. before 12:00 Midnight, which in practice often means before the next morning when Prof. Griffin arrives in his office. Note that the delivery of overdue HW is your responsibility: the Physics building is sometimes locked in the late evening. (Also, do not confuse overdue HW with overdue lab reports which must be placed in the Physics 117 Lab Mail Slot in the wall near Physics Room 3316. Please do not submit lab reports at any location other than the Lab Mail Slot, nor HW’s at any location other than Physics Room 2109 .) Late homework will not be accepted. If you must be away on a homework due date, turn in your homework early. Missing one or two HW’s can be penalty-free under the 80% rule discussed below, which is designed to allow you a miss or two for illness or other reasons, albeit with a corresponding reduction in your flexibility . But if some set of ongoing or recurring difficulties repeatedly prevents your submitting the HW on time, then the matter should be discussed with Dr Griffin.


Note that overall HW (and Lab and Participation) grades will be determined on the ``80% is Enough'' basis: everyone who gets 80% or more of the maximum possible total semester score will be given the same maximum raw grade of 100%.  See the more detailed discussion under GRADING POLICY. This scheme reflects the fact that HW, LAB and Participation are learning processes where perfection is not to be expected.  But note that ``80% is Enough''  places a heavy premium on achieving a full 80% on these items, since nearly everyone will do so, and those who do not may fall seriously below average after renormalization exaggerates their deficiencies..


The assignments for the first part of the course are listed in HWAssignments.