CSUSB PHYSICS
221 Lab
WINTER
2015
Timothy D. Usher, Ph.D.
Office: PS-115
Telephone: 880-5410
E-mail: tusher@wiley.csusb.edu
Web Site: http://physics.csusb.edu/~tusher/
Main Physics Office: PS-119, Telephone: 880-5397 www page
"http://physics.csusb.edu"
Required Textbooks: Physics 221 lab manual; provided in digital form as part of your lab fee.
Recommended Textbook: An Introduction to Error Analysis
by John R. Taylor. The introduction is particularly recommended.
Computer software: Graphing software is available in PS 104. Other
software is also available. In addition, the internet can be accessed from PS104.
Corequisite: Physics 221
(class)
Note: An F in laboratory results in an automatic F in
class!!!!
General course goals: My
goals as your professor are as follows:
1. Help you build conceptual tools and basic knowledge of Physics.
2. Help you improve your ability to think.
TENTATIVE SCHEDULE: We will begin with experiment number 1 and proceed in order through experiment number 9.
FINAL
A lab final will be given on March
19 (NOT during finals week). This final will determine 25% of your
laboratory grade. The final will cover all of the labs during the quarter, so
don't just do them and forget them! Some students have a tendency to just run
through the motions without really thinking about the lab. One purpose of the
lab final is to encourage students to THINK about the labs. The lab
final often determines the grade distribution because students tend to get
similar grades on labs.
GRADING
IT IS ESSENTIAL THAT YOU ATTEND EACH AND EVERY LABORATORY !!!! A TOTAL OF THREE
OR MORE MISSED LABORATORY REPORTS RESULTS IN AN F FOR THE LAB!
If you do not attend a laboratory,
you cannot hand in a laboratory report and you will receive a 0 for that
report. A total of three or more missed laboratory reports results in an F
for the lab regardless of the average and an F in laboratory results in an F
for the overall course!!
For labs 6 and 8 you must have
me initial your data sheet before you leave. The laboratory equipment is
taken down each week so there are no make-up labs after the equipment
has been taken down!
It is important that you read each lab manual write-up before coming to
lab. I will give pop quizzes to encourage this practice if necessary. You
may be able to complete parts of the lab before coming to class. It is also
important that you arrive on time. Important instructions are given at the
beginning of each lab session. For labs 6 and 8 you will write-up a full lab
report. The report is due at the BEGINNING the following lab session. For the other labs
you will do a worksheet. The worksheets are due the same day. Even
though you will work on the labs in pairs, each student will hand in a separate
spread sheet or lab report.
It is generally expected that students do well in laboratory and that this will help improve the course grade. You may find it quite easy to get a C or D on lab reports; however, the reports must be outstanding in order to receive a 100. The final numeric grade will be reported to your instructor with a copy of this grading scale. It is ultimately up to the lecture instructor to determine how to incorporate this final grade into your overall grade.
The grading of a laboratory report is necessarily subjective in part. The following main criteria are used: 1)Did the student do all of the required parts of the lab? 2) Does the student clearly communicate a clear understanding of the subject? 3) Were the results of the experiment in keeping with what is to be expected? If not, why not? You will not be graded on your percent error or percent difference. If however, it is off drastically this is a clue that you should recheck things. The following criteria are also used in determining the grade. 1) A clear understanding of the physics principles covered in the lab must be communicated. 2) A clear, concise presentation of the objective, data, calculations, results, discussions, observations, and conclusions. 3) Reasonable care with significant figures and accuracy. 4) Correct grammar and spelling. 5) Well constructed data tables and graphs.
NOTE: A long lab report does not mean a good grade. In fact, it may detract from the grade if the report is unnecessarily wordy. So, be concise! Technical writing is perhaps the most difficult form of writing so don't be surprised if it does not come so easily.
IMPORTANT NOTES:
- SAFETY FIRST!! Always be very careful. If you are unsure, ASK!
- Keep this handout!
- Thoroughly read each lab before coming to lab! Some labs will require graph
paper or you may use the graphing software in PS104.
- A simple calculator with the following functions will be of use: sin, cos,
and square root.
- If you have a laptop, it might be
useful to bring it.
- It is important to be on time. Critical instructions are given at the
beginning of each lab!!!
- Honesty is expected. Dishonesty will be dealt with harshly. Cheating, or any
other form of dishonesty will result in an F for the lab!
- You will work with a lab partner. It is expected that each person contribute
equally. I will check to see that this is the case. Of course, your data will
be the same. I suggest that you check each other's calculations and discuss the
questions posed in the lab manual. You will turn in separate lab reports. The
lab reports must not be virtual duplicates. If this happens, both
reports may receive a zero.
- For labs 6 and 8, I strongly recommend that you complete as much of
the lab as possible during the lab period for a number of reasons. 1) I am
readily available to consult with you. A student who rushes through a lab and
then spends the rest of the week trying to figure out what she/he did. 2) The
longer you wait to write-up the lab the more difficult it is to write-up. 3)
The laboratory equipment is moved around, changed or even put away after you
leave, making it impossible for you to finish the lab if you forgot to make one
small measurement. 4) You should at least calculate a final answer and check to
see if it makes sense before leaving. Remember, you must have me initial your
data sheet before you leave anyway. A late lab (one that is not turned in at
the beginning of the meeting) will have 10 points deducted from it. A lab that
is over one week late may not be accepted at all!!!!
- I strongly urge you to keep a laboratory notebook, a sort of a diary.
Many laboratories require this. It is much more difficult to lose a lab
notebook than lose scraps of paper.
- Save all of your returned lab reports.
- Notice that most of the equipment has been well maintained; please help us
keep it that way so we can help keep education cost down. Anyone caught
defacing or intentionally damaging or stealing laboratory equipment or
furnishings will be reported to the department chair.
- Be sure to ask questions. The only dumb question is the one left unasked.
- We are all human and deserve to be treated as such, so, if you have any problems
please see me about them.
- If you have a concern about your grades, be sure to speak with me before
taking any drastic measures.
- Audio/Visual aids (films, videos, computer programs, etc.) are available.
- Many services are available at the University:
- The laboratory should be a very enjoyable experience. The atmosphere is more
relaxed than in a classroom. In fact, I feel that the laboratory experience
most closely resembles what Physics is supposed to be. One seeks understanding
from Nature itself.
THE LABORATORY REPORT
It is extremely important is to be clear and concise in your
report. The reader should be able to look at your report and quickly: 1) see
what the lab was about, 2) check the data, 3) check the calculations 4) check
the validity of the results 4) understand any discussions and the conclusions
that were drawn.
The lab reports must be neat... (label each section) They should be NEATLY written or typed. You can also mix writing and typing. For
example, you may want to write out the equations and such, while typing the
text.
- do not tear paper out of a ring notebook leaving the "fuzzy" edges
- be sure to staple your labs together
- do not write on the back of a sheet of paper
The lab reports will have the following format. Clearly label each section.
I) Objective
II) Results and Discussion
III) Observations and Conclusions
Objective:
A short statement (one or two sentences) in
one's own words of what the aim(s) or the goal(s) of the experiment are. If
some thought is given to this before coming to the lab, it will go much better.
Results:
Here is where you give your answers. Be sure to show your raw data before doing
any calculations. If the answer is numerical, show all of your
data, your calculations, and results. It is important to use always units in
your calculations. If the answer is not numerical (i.e. yes/no or answering a
question), state the question, your answer and your reasoning. A common mistake
is that students sometimes simply overlook a question. Double check and make
sure you answer each question and make it clear which question you are
answering.
Observations and conclusions (Very Important):
The importance of this part cannot be over stressed. Here is where you tie it
all together. Look back at your objectives. Tell if you reached them or not;
why or why not? Capture the essence, or the key idea behind the lab. Also,
creativity may be called for here. Make your report interesting! Any machine
can take data and many can interpret the data. Show that you are more than a
machine.
EXAMPLE
Your
Name ____________
Your
Partner's Name ____________
Section
Number ________
Title of Experiment
Experiment Number
Objective:
Determine the speed of a nervous person pacing back and forth.
Results:
1) Length of room L = 10.00 +/- 0.01
meters
2) Times for trips across room
Trip number
Time
+/- 0.5 (seconds)
1
5.0
2
4.5
3
5.5
4
5.0
5
10.0
neglected, subject
stopped
6
5.0
_______
Average
5.0
3) speed = distance/time or v = d/t v = 10.00m/5.0 s = 2.0 +/- 0.2 m/s
error calculations
dq = q { dx/|x| + dy/|y|} = 2.0{0.01/10.00 + 0.5/5.0} = 0.2
Observations/Conclusions:
It was determined that this nervous person has an average speed of 2.0 +/- 0.2 m/s. If one assumes that the degree of nervousness is directly related to the speed, then one could get a quantitative indication of how nervous the person is.
In order to compare with more familiar units speed is converted to miles/hour or mph.
Conversion factors: 3600 s = 1.000 hr and 1.000 mile = 1,609 meters
2.0 +/- 0.2 m/s x 1.000 mi/1,609 m x 3600 s/1.0 hr = 4.5. +/- 0.4 mph