PH111L - Physics I Lab

Fall Term 2014

General Information

Instructor:    Galen C. Duree Jr., PhD

Office:    Room DL102                       Phone:    872-6025                                 Box:    182


Office Hours:      9:30 AM - 11:00 AM   T Th  &  4:20 PM - 5:15 PM M T  Th F

The second series of experiments, entitled "Newton's Second Law" (a description of which can be found in the lab manual beginning on page 77), were performed in BL113 last week.

The lab reports for the "Newton's Second Law" experiments are due in the green bin outside my office by 5:30 PM, one week after you performed them in the lab.

 Section 52 lab reports are due on Monday, Oct. 20.

Section 53 lab reports are due on Friday, Oct. 24.

For this experiment, the purpose is to evaluate the model for the acceleration of a system presented for your particular experiment.  Remember to do all of the curve fits in Logger Pro.  Use only the position vs. time graphs, not the velocity vs. time graphs for your calculations (the analysis of the velocity vs. time graphs is optional).  Include, at a minimum, four graphs:  the one graph showing the levelness of the track with parabola fits on each side (place this graph in the Analysis Section), one sample data graph with NO curve fits on it (in the Procedure Section), one sample graph showing at least one curve fit (showing the fitted parabola and the equation parameters) and, finally, the plot of acceleration vs. the mass ratio with a line fit and error bars on the data points.  In order to make the error bars, you will need to propagate the uncertainty in the mass ratio - make sure that you calculate it or you will get a low lab report grade!  Remember to make a comment about whether the model is appropriate for your experimental situation or not.  You are NOT investigating Newton's Second Law, just a model for the acceleration of the system you are working with.  In the analysis section, be sure that you list explicitly the values you obtained from each data file.  You do not need to show how you got each one, but you must list all of the values that you used.  If you find that the model is not a good one, list some factors that you think may have contributed to the situation in the conclusion section of your report.



The description for Falling Bodies:

Remember that there are two things that you are asked to do:  (1) Determine the free-fall acceleration of a plastic ball and (2) evaluate the model of drag force proportional to the terminal velocity squared.  While preparing the lab report for this experiment, remember to do all of the curve fits in Logger Pro.  Use only the position vs. time graphs, not the velocity vs. time graphs, for your calculations.  Include, at a minimum, five graphs:  two raw data graphs (to be placed in the Procedure Section), one for the ball and one for the coffee filters; two graphs showing at least one curve fit (to be placed in the Analysis Section); one for the ball and one for the coffee filters; and a graph of the drag force vs. terminal velocity squared with error bars.  If you need help, please don't hesitate to ask!  To summarize, there should be, at a minimum, five graphs included in your report.  Please also remember that it is department policy that there be one graph per page and the graph should be the only thing on that page.  You do not have to worry about resizing your graphs so that they fit the page exactly, just get one graph on the page and make sure that it fits completely within the borders of the page.


Download a copy of the Error Analysis Worksheet

The next labs, entitled "The Simple Pendulum", will be performed during the week of October 27, 2014.

Lab Report Format

A complete lab report must have the following sections:

Do not forget to update your Table of Contents and to number the pages in your lab notebook!

The first page of your report must have a title, the name of the P.I. (explicitly indicate who was the P.I.), the name of the lab assistant, and the date that the report was turned in (not the date that you performed the experiment!).

*Abstract - a BRIEF description of what you were investigating, how you conducted the experiment and your conclusions based on your experience.  The abstract should not be a discussion of what you are going to do in the lab.  The abstract cannot be written before you have analyzed your data.  In the lab notebook, skip a page or two so that you can write this in at the beginning of the report after you have analyzed your data.

Introduction - a discussion about any details that you think would help someone perform the experiment.  This should include a discussion about the model (equations that you are using) or the method selected for performing the tests.  If you use models (equations) in your analysis, list the models in this section and describe what each of the variables represent.

**Procedure - a detailed description of what you did in the lab.  At the beginning of this section, place the date and the time that you began the experiment.  This section must include a schematic, detailing how things were connected, where appropriate.  The raw data must appear in this section immediately following the description about how the data was taken.   A person must be able to read your procedure section and be able to duplicate your results without having the lab manual present.  Do not do any calculations in this section, just record how you performed the experiments and record the raw data.  If the data is taken by computer, you must specify the path and filename where the data is stored.   This information must be listed in this section right after the description of how the data was taken.  Do not simply list all of the files generated at the end of the section.

This section MUST be signed by the instructor before you leave the lab.  If you turn in a report without the signature, it will not be accepted!

Analysis - a sample of the calculations made in the lab.  This section should include a sample of the error calculations and propagation of errors used in your analysis.   The final data that you are analyzing to generate conclusions, the values with appropriate uncertainties, must be shown in this section.  The actual calculations for each one does not have to be included, as long as you show an example for one, but you may include them all if you wish.  The calculations may be done by the computer, but include printouts of the worksheet in your lab book.  Any graphs or printouts that are placed in your notebook must occupy one whole page and be trimmed to fit within the page and not hang outside of the notebook.

*Conclusion - this section must have a conclusion that is based on your experiments and analysis.  If your conclusions do not following logically from your analysis, your grade will be deducted significantly.  This section must also contain a brief description of significant factors that you think affected your data, in particular, the uncertainties in your data (factors that contributed to the error in your experiment).  A good thing to keep in mind is to think of this report as a report you are submitting as part of your job responsibilities.   If you do not think your boss would accept what you have to say, it is a safe bet that I will not like it either.

The asterisks indicate the sections that I will pay closest attention to.

Modified October 20, 2014 by Galen C. Duree Jr.