Computer Interfaced Experiments for Introductory Physics

Computer Interfaced Experiments for Introductory Physics

William P. Crummett
Centre College

Final Report
May 29, 1998 I. Objective

The objective of this project was to write ten new laboratory exercises for the first term of the sophomore, introductory physics laboratory. Six of the exercises were to utilize the Pasco, Science Workshop (SWS) Interface, and nine of the ten exercises were to apply Quattro-Pro for data analysis. During the Fall-1997 term the following laboratory exercises were written and used in all three sections of PHY-21 lab:

Experimental Error-I

In this traditional experiment students roll a ball down a tube so that it launches horizontally. The horizontal travel distance is measured for six different tube heights. With these data students learn to confirm theory by fitting a linear relationship by hand on a graph of the data.

Experimental Error-II

Students learn to use a spreadsheet by re-analyzing their data from the previous week's experiment.

Inertial Balance

An unknown mass is determined after constructing a calibration curve of mass versus period of motion from an inertial balance. Students learn to use the spreadsheet's regression analysis package.

Motion Graphics

The Pasco SWS software and motion sensor interface are used to measure and observe the relationships between position, velocity, and acceleration of a glider on a level and then inclined airtrack.

Newton 's Second Law

The SWS interface and the rotary motion sensor are used to measure the relationship between force, mass, and acceleration for a glider on an airtrack. Data are analyzed by spreadsheet.

Collisions and the Impulse-Momentum Theorem

The SWS interface, motion sensor, two photogates, and a force transducer are used to investigate impulse, momentum, and the conservation of momentum for gliders on an airtrack. Data are analyzed by spreadsheet.

Conservation of Energy

The SWS interface and a rotary motion sensor are used to record the relationship between potential energy and kinetic energy for a glider pulled along an airtrack by an attached string that passes over the rotary motion sensor to a hanging mass. Data is transferred electronically to a spreadsheet for analysis.

Moment of Inertia

The SWS interface and a rotary motion sensor are used with a traditional moment of inertia table and a hollow ring to measure the ring's moment of inertia. Data are analyzed by spreadsheet.

Compound Pendulum

The rotary motion sensor is used to measure the period of a meter stick that is pivoted about a series of axes along its length. Data are analyzed by spreadsheet.

Vibrating Strings

A spreadsheet is used to analyze data from this traditional experiment: The relationship between the tension in a string and the wavelength of the resulting standing wave is measured.

II. Project

The SWS interfaces were purchased, tested, and implemented during this project. However, the college made the decision to adopt the Excel spreadsheet package as the campus standard, so the exercises were written for this software rather than Quattro-Pro, as indicated in the original proposal. This change turned out to be very positive because Excel proved to be superior to Quattro for our applications.

In the proposal there was to be only one week devoted to the analysis of experimental data and an additional experiment utilizing the variable-g pendulum was included in the ten experiments. However, when the experimental analysis exercise was being modified from past years it became apparent that two weeks were still necessary for this exercise. The decision was made to omit the variable-g pendulum experiment. In retrospect, this choice seems to have been a good one.

During the fall term a log was kept for corrections and possible changes to each exercise. There were typographical errors in most write-ups and a few instructions required clarification. Moreover, preparation for the presentation at the January AAPT meeting (see below) resulted in several printouts of graphs and sample data that made useful additions to the write-ups. During the winter term each exercise was rewritten.

To obtain some student input about the success of the project, a survey was developed. The survey sheet is provided in the appendix with the results indicated in a column to the right of the response area. Overall, the changes to the laboratory were well received by the students. Antidotal comments by the students indicate they enjoyed the interface experiments and felt the lab had a distinct modern flavor to it.

III. Dissemination

So that other physics faculty can benefit from this project two presentations were given on the project and its outcome. The first was at the January 1998, meeting of the American Association of Physics Teachers in New Orleans. The talk was well received by about fifty college and high school physics instructors. Also present in the audience was Paul Stokstad the founder, owner, and CEO of Pasco Scientific Company. After the talk he requested copies of the new lab exercises.

The second talk was given at the spring, 1998, meeting of the Kentucky Association of Physics Teachers. About three dozen college and high school physics instructors from Kentucky and Ohio attended this presentation. It was also well received.

IV. Future Work

The interfaced experiments have proved so successful that the physics program members would like to continue to develop additional exercises for the second and third terms of the course. This project has generated ideas for interface experiments in the areas of sound, thermodynamics, and optics.

A long-range goal is to replace the Excel spreadsheet with a software package that is more appropriate for scientific applications. Students who go on to careers in science would benefit from learning to use a program such as Origin or Sigma-Plot.

Appendix

Physics 21-Lab Survey

Direction: Put an x on the scale at the location that best answers the question from your own perspective. Do not put your name on this survey.

1. Did the lab exercises help you understand concepts from class?

	0	1	2	3	4	5		Result
Never							Always	3.65

2. How did you find learning EXCEL?

	0	1	2	3	4	5		Result
Difficult							Easy	4.27

3. How did you find learning the SWS software?

	0	1	2	3	4	5		Result
Difficult							Easy	4.01

4. How did the this lab compare to other labs you have taken at Centre in the area of:

(a) Difficulty

	0	1	2	3	4	5		Result
Difficult							Easy	3.00

(b) Demand on you out-of-class time?

	0	1	2	3	4	5		Result
Small							Lots	1.29

	0	1	2	3	4	5		Result
No Time							3 hours	2.08

(d) Connections to lecture material.

	0	1	2	3	4	5		Result
None							Lots	3.95

(e) Your overall enjoyment of the lab.

	0	1	2	3	4	5		Result
Awful							Great!	3.81

5. Learning to use the computer and software detracted from learning physics...

	0	1	2	3	4	5		Result
A Lot							None	4.21

6. The equipment functioned properly so that it was possible to obtain accurate data

	0	1	2	3	4	5		Result
Never							Always	3.75

7. My instructor was prepared and could answer my questions.

	0	1	2	3	4	5		Result
Never							Always	4.26

8. Which experiment(s) should be improved or eliminated and why?

Fall 1997 ACS-Mellon Technology Fellows
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