- Write formulas you use on each question template (e.g., PE =
0.5 * m * v2), as per Lab PPT slide 7
- DO A “REALITY CHECK” on your answers- In Q8 if you get
displacement x to b e a very large value,
for example 210 inches, you should think about the physical significance and
realize there might be an error (we understand the examples may be very
hypothetical, but you should still ask if your answer makes sense)
- Things that are not limitations: The physical model of the
collision, the fact that you were given lab data instead of measuring them
yourself.
- Please avoid inserting symbols (arrows, etc.) unless it is
in the equation at the top of your sheet.
- Please continue to use appropriate significant figures. For
example, do not write 13856.32 lb/in2, where 0.02 lb/in2 equals
to stress caused by a weight of 0.32 oz laying on a 1 sq.inch surface. You will
drastically overestimate the accuracy of your work, especially on a structure
like the T-P Bridge pier. Scientific notation may mask an unrealistic computed
value (e.g., 2.3E-22 lbs), so be careful, or use common notation with an appropriate
rounding and sig figs.
-For the potential energy, you needed to consider that each
of the two legs of a pier can absorb some of the impact of the tanker (multiply
by two in question 3). For displacement of the bridge, the legs of the pier
move together and therefore you should not have accounted for a factor of two
there (Do not multiply by two in question 2, but consider in question 5 that
Pyield is per pier). The words “per pier” or “for both piers” were explicitly
stated in each question at the top of the sheet, question 6 asked for EACH
pier. For question 7 do not account for factor of 2. For each question, you had
to specify which approach was correct for that problem (not just write down
both) and highlight your answer.
- ~25% of all errors are with UNIT CONVERSIONS! Please be
careful when applying conversion factors.
Other feedback and
general comments:
- We understand that
in some cases you will need to think about the problem. These labs are not meant to be just plug-in
exercises.
- If you do not have access to Excel or a computer, the CAD
lab and Korman building have resources available. OpenOffice Calc will also
work with the templates.
- If you have been working in groups, consider switching
your group members each week since some of you are making the same mistakes from
week to week. You MUST turn in your own original work. Do not reuse work from
previous semesters of this course.
