Introductory Physics I: Mechanics and Wave Motion Lab

Courtesy of Prof. Bourgeois:

Here comments concerning your first lab reports. I hope you find this comment useful and apply them to your next report on Inclined Plane.

1. Formatting:
   1. Make sure values have appropriate units and significant figures. As a rule of thumb uncertainties are stated with only one significant figure and the best value has the same number of decimal places as the uncertainty.
           Example: g = (9.78+-0.03)m/s^2 NOT g = (9.7845+-0.027445643)m/s^2
   2. Don't separate best value from uncertainty when stating a result. State a result in the form of the above example.
   3. Label equations with a reference number, usually along the right margin. When referencing an equation in the text of your report, simply say Eq.(#) Where # is the number of the equation.
   4. Make sure points in a graph fill the whole graphing and are not squished to one side.
   5. Follow the outline in the Appendix on Formal Reports to organize your report. Be careful not to mix sub-topics of your report, i.e. analysis in the experiment procedure section or theory in the analysis section. Use subheading to help organize your report.
2. Composition:
   1. Check spelling and grammar.
   2. Use terminology correctly. Some students confused words velocity with acceleration or acceleration with force.
   3. Keep the writing style a simple as possible. Don't be bombastic - grandiose or inflated language. Some students wrote in their reports how the experiment of the bouncing ball would "prove the fundamental principles of physics" or "advance our understanding of the law of gravitation". These are gross over generalizations, the bouncing ball experiment is just a simply kinematic experiment about constant acceleration.
   4. Don't use slang. Example:"I plugged my values into the equation and got g." The word "plugged" is a colloquialism. I better way of saying the same thing is "using Eq.(3) and my best values of L, a and h, I calculated g."
3. Content:
   1. Stay on topic. Avoid verbiage - extraneous and excessive wordiness.
   2. Don't digression from the subject manner. For example, don't over explain the sonic ranger or air track. The experiment is about the PHYSICS of motion along and inclined plan, not the devices use to demonstrate the physics. Just a few sentences a needed to explain the air track.
   3. You are accountable for everything you write in your report. So watch out for illogical, obtuse, conjecture, specious or erroneous statements. Anything you write in report should be backup by the evidents you have acquired (data, graphs, equations, results, etc.)

Courtesy of Prof. Bourgeois:

Here are some specific instructions for you as you write you next report on the inclined plane experiment.

1. Each student should analyze two sets of sonic ranger data, one for each riser to elevate the air track. You do NOT have to analyze all the sonic ranger data taken by your lab group as the manual implies.
2. When analyzing the preliminary experiment using the stopwatch, I recommend you calculate 5 values of acceleration a, one for each of the 5 times you measure using the stopwatch. Then the best value of a is the average, and uncertainty of a can be estimated using the high-low method. Now will have a best value of a, L and h and their respective uncertainties to propagate when you calculate g.
3. Even though this is a formal lab report, you still must have a COMPLETE record of the experiment in your notebook. Just as professor Darnton stated at the beginning of the semester, there is a bare MINIMUM of things you should have in your notebook: Title,Purpose, sketch of apparatus, outline of Procedure, Outline of Analysis and Results, Summary. For example if your analysis includes plotting graphs and performing a regression analysis, then those items should go into your outline of Analysis. There is an order to how science is done: first you do the research, then you write the paper.
4. Keep detailed calculations in your notebook. For example you do not have to present a detailed calculation on how to propagate the uncertainty of g. Just reference what equation you used and state result.

General comments on writing your first formal lab report, many of which will apply to all the formal reports.  Courtesy of Prof. Bourgeois.

1. Read and follow the guidelines the Appendix D on Formal Reports in your lab manual. I also attached a sample report to this email to give you a visual of how to format your report.
2. Even though this experiment is a formal report, you are still expected to COMPLETELY document the experiment in your notebook. Remember, your notebook should be a complete record of the experiment from introductory remarks to summary and conclusion. I taught this lab long enough to catch on that students often start writing reports as soon as they finish the lab, but you are still responsible for recording your lab work in your note. There is an order to this process: notebook first, formal report last.
3. I feel I need to emphasize that you are all bound by the college's code on Intellectual Responsibility. As the manual states we do encourage discussion between partners about data and analysis. But once the discussion is done and the writing begins all communication between partner should stop, both in person and electronic. The reports you will submit represent your individual understand of the subject matter. Often when students write together, even if they do not share drafts, there is a lot of "cross talk" and it is hard to distinguish whose ideas are truly their own.
4. Your reports are due Tuesday, Sept. 30th, no later than 5pm.
5. Do not include long tables of data in report. In fact for this particular report you do not have to include any table as long as your data is presented in a graph.
6. Do not answer questions as if you are answering a questionnaire. Instead incorporate your answers into the body of the text. The purpose of the questions are to motivate the discussion. Every question should be answered with an implicit "why?" Always answer questions from a physics point of view.
7. Do not give detail instructions on using Sonic Ranger or Excel. The particulars of the software or the instrument used are not interesting to the reader. In the case of Sonic Ranger it is sufficient to explain how the sonic ranger use sound pulse to measure position of an object. You don't have to write a manual.
8. Do not include the "Summary Output" page from the regression analysis in your formal report. Keep that in your notebooks. Just extract the relevant results.
9. Watch your UNITS and Significant Figures!!! Programs like Excel do not understand either, so it is your job to keep track of them. The accepted convention is uncertainties almost always be rounded to one significant figure. Your best value should be rounded to the same number of decimal places as your uncertainty. Always present best value and uncertainty together.
10. I will allow hand drawn diagrams of the experimental setup, but please use tools like rules, no free-hand diagrams.
11. For now you can assume the sonic ranger is a precise instrument. Any uncertainties will manifest themselves in the uncertainties from regression analysis.
12. When plotting average velocity vs. time make sure your points fill the whole range of the graphing window. When selecting a "good parabola" you may select one that started 2 or 3 seconds after starting the sonic ranger. It is not necessary to have a zero on your time axis.
13. Some students asked whether they should include the hand draw graph from the "Preliminary Experiment" and if they should answer Q1 and Q2 in the manual based upon the hand drawn graph. Here is what I say, you do not have to include the hand drawn graph, keep that in your notebook. Instead, include the graph of position vs. time you get from the sonic ranger and answer Q1 and Q2 base on that.
14. Eliminate verbiage. For example, if your reader is someone who has an   equivalent background of a P16 student, then you can assume the reader knows the meaning of kinematic terms like velocity (dx/dt), average velocity (x2-x1/t2-t1) and acceleration (dv/dt). Don't spend time defining these terms. Just state the specifics of these kinematic quantities for a bouncing ball.
15. Eliminate redundancies. Here is another example. If you have an equation defining velocity like v=dx/dt then it is not necessary to write a sentence "velocity is the derivative of position with respect to time...". Again, you can assume your reader has a basic knowledge of differential calculus, so it is not necessary to define a derivative.

Prof. Bourgeois will be available to field questions and check drafts via email.