WebHW Guide
Note: this page contains information on WebHW. For information on how to use
iLrn, go
here.
Introduction
All homework in Physics 222 will be administered via this World
Wide Web (WWW) site. This means that you must seek access to the WWW in order to
submit and receive credit for homework in Physics 222. You have many options for
arranging the necessary access:
- RH 123 will be open during times posted on the door.
- There are several computer laboratories on campus that you may use (e.g.,
laboratories in Robinson, and Karpen Halls). See http://www.unca.edu/compcenter/labs.html.
- Computers with WWW access are located in many of the residence halls.
- Of course, the best solution of all is for you to have a computer at your
home or in your dormitory room with WWW access. Ethernet access is great,
but modem access will work just fine for WebHW problems. Every effort has been made to keep the
graphic content of the problem content as small as possible. Transmission delays for
modems as slow as 14.4 kB should be no more than a few seconds for any given
problem. Note: streaming video content associated with this
course (but not WebHW) will NOT work via modem access.
Please don't fret if you lack experience with WWW browsers or even the WWW in
general. Feel free to contact Bennett at any time for assistance.
Browser
Microsoft
Internet Explorer is best, but Netscape
will work fine. Both work with PC's (Intel) and Mac's.
Cookies
You must must have your browser configured so as to allow
"cookies" in order for this page to function properly. Cookies are
bits of information stored on your hard disk. They do not take much space and
are not insidious. Please see Bennett if you have questions.
Content Caching
Browsers typically store local copies of pages that you have visited
previously. This causes problems with WebHW, since problem parameters are
often set randomly. If you are working from a cached page, the parameters
you see may not be current, and WebHW will tell you the problem has been worked
incorrectly even if you supply a correct answer for the parameters you
see. The solution: set your browser to check for new content
on every visit to every page.
Here is how:
- On Internet Explorer, click Tools on the Menu Bar, the select Internet
Options... . Then Click the Settings... button in the middle of
the window. At the top of the next window, make sure that the Every
visit to the page radio button is selected. Click OK
twice.
- On Netscape, click Edit on the Menu Bar, the select Preferences.
Click the Advanced button, and then click Cache. Make sure the Every
time I view the page radio button is selected. Click OK
twice.
Password Caching
Yikes! This is a bad idea. NEVER save a password for future use
on a lab computer. Why? Because the next person using that computer
can use that password to get into your account. This is not as bad
as it seems, because you cannot hurt your homework grade while working in
WebHW. Still, you should be careful.
By the same token, Auto-complete should be turned off if using a public
computer. The computer center is supposed to configure lab computers this
way, so if you notice that it is not, contact Bennett.
Calendar
The WebHW calendar is linked at the bottom of every WebHW problems. The
calender contains all assignment due dates, and other important course
events.
Due Dates
The site is subdivided into 16 subject areas, and there is an associated
homework assignment in each area. You will find the due date for all assignments
on the WebHW calendar (see above).
Assignments
WebHW assignment are linked from the individual chapter areas of this
site. Each assignment listing contains a short problem description.
Click the link for more details.
Problem status is communicated by the following icons:
A
green light means that the due date for this particular problem
has not passed. After working this problem, you will receive credit towards your
final homework grade.
A red
light means that the due date for this particular problem has passed. You
may still work the problem. In fact, it is good practice to do so. The
only difference is that you will not receive any "points" toward your
final homework grade for problems submitted after the due date.
A smiley
face means that you have already received credit for working that
particular problem. You may work the same problem as many times as you
like. As explained below, the details of many of the problems change
each time you log on, so you may find it useful to work the same problem more
than once.
All problems carry equal weight. The fraction of smiley faces that you have
will allow you to monitor your homework grade. There is a status area at the
bottom of each problem where you can see the point value for the problem, and
the percentage of others in the class that have already solved the problem
correctly.
Note: credit received for any particular problem is permanent!
There is no way you can hurt your homework grade by attempting a
problem for which you have already received credit, even if you miss it on a
retry. Also, no records are kept on unsuccessful attempts at any problem. Only
correct submissions are recorded.
This deserves restatement: you can not hurt your homework grade
in any thing you do here -- you can only increase your grade. Tinker as much
as you like!
Logging On
Your password will be set initially to you social security number (no dashes or
spaces). You can change your password at any time by clicking the Change
Password link on the log in screen. It is probably in your
best interest to keep this to yourself, but be assured that if someone steals
your password and logs onto your account, the culprit can only increase
your homework grade.
Guests may currently access this site via the log-in page. Of course, no records
are kept for guests, and only "green lights" are displayed by
problems.
To keep life interesting, problem details will change whenever:
- You invoke a new browser.
- Two hours pass from the last time you submit a solution.
Submitting an empty or incorrect solution will restart the clock!
You are encouraged to work in groups, but each person in your group must work
within their own individual browser logged into their particular account. Any
given problem displayed in different accounts will utilize different problem
parameters and so will require different answers. Sharing answers will not
work!
Because of this, you are encouraged to work WebHW problems collaboratively.
No Credit Until the Problem is Complete
You must work every subpart of a problem correctly before you receive any
credit. Its all or nothing -- there is no partial credit. Keep in mind the
following:
- You will see a summary message telling you when you have received credit
for any particular problem. You should also see the "green light"
change to a "smiley face" when you return to the assignment
page. . Occasionally,
you might need to "refresh" or "reload" the summary page
to see the smiley face appear.
- You cannot skip subparts to a problem. Every question must be answered
correctly before you receive any points.
Important: every effort has been made to make this site unhackable.
Hack all you want, but if you find a hole, you MUST report it to Bennett.
Successful hackers who report the problem will receive my unbridled admiration
and gratitude. Successful hackers who exploit a problem and do not report it
will receive a failing grade in Physics 222.
Numbers
Many of the problems require numerical input. Your answer must be
accurate to three digits in order to be accepted as correct. Integer answers
must be exact.
Scientific Notation
Numerical input utilizing scientific notation are entered as they are on most
calculators: i.e. 3.00 x 108 is entered as 3.00E8
Constants
To achieve the necessary accuracy, always round physical
constants to four digits of accuracy. For example,
- the speed of light in vacuum rounds to 2.998 E 8
- Pi rounds to 3.142
- the Coulomb constant ke rounds to 8.988 E 9
Problems with Incorrect Answers
Special deal: Every effort has been made to eliminate all
bugs from WebHW. However, it is possible that bugs still exist. The first person to
report an incorrect answer to me (by email) will receive an extra point on their
homework grade. If you are working as a group and find an incorrect
answer, then everyone in the group gets a point - one email message listing
everyone in the group will suffice.
Note: Bugs will be rare. Just because you don't get the right answer does not mean the problem is
incorrectly programmed.
Getting Help: Your Homework Solutions Manual
Experience has shown that web homework is extremely effective at motivating
good problem-solving skills. It is important to get into the habit of
maintaining detailed problem notes - preferably in a homework manual dedicated
to this purpose. In particular, it will be very hard for me to help you
with a given problem unless I can see from your notes where your difficulty
lies. I can only give detailed help if you bring detailed
notes along. If you have difficulty getting started on a
problem, I can give you a shove in the right direction, but you should
not expect me to work problems out for you that you have made no progress on.
WebHW Software
To learn more about the WebHW software, visit the WebHW
Site.