Physics 22 Laboratory Report

Experiment O1:

Measurement, Errors, Data Studio

Prepared By: ______Date:

Partner: ______

Lab Instructor: Lab Section:
Spring 07
Remarks by Grader:
Grade:

EXPERIMENT O1: Measurement, Errors and Data Studio

OBJECTIVES:

1. Review Laboratory Report Format.

2. Review Error Analysis and review use of EXCEL for analysis and plotting.

3. Learn to use Data Studio, the data acquisition and analysis software used in this laboratory

Reading:

Supply the appropriate reference to your textbook. Title, Author, Page(s).

PART ONE: Data Studio

Introduction: This is a short experiment to review use of EXCEL and to introduce studentsto Data Studio.

Apparatus: You supply.

Procedure:

  1. Connect two Photo-gates to the Science Workshop 750 ports.
  2. Start Data Studio
  3. Chose photo-gate from sensor list and drag to correct ports.
  4. Click on “TIMERS” from the upper bar. Label as desired. From “timing sequence” setup to measure the time the glider takes to go from gate 1 to gate 2. Click “DONE”.
  5. With a level air track, give the glider a push and determine its average velocity between the gates.
  6. Repeat several times.

Measurements: Paste a table of your measurements here.

Analysis:

  1. From your measurements with the photo-gates, determine the velocity of the glider for each trial.

Conclusions:

Part One:

Part 2 next page

PART TWO: Measurements and Errors

Introduction:

1. In this laboratory, we often calculate a quantity, such as g, from measured quantities. All our measurements have errors, and we need to know the error bars for the calculated quantity, due to the measurement errors. Start with an example:

We have measured the length of the two sides of a rectangular plate and wish to calculate its area. One side was found to be length a and the smallest division on our ruler was a, so we claim that the length of this side is a ±a. Similarly, for the horizontal side we find a length b±b. We suspect that our best estimate for the area of the plate is A = ab, but what error bars should we attach to A? At look at the diagram indicates that the smallest area would be AMIN = (a-a)*(b-b)=ab - ab - ba + ab  A- ab - ba  Similarly, the maximum expected value for A is AMAXA + (ab + ba). We have assumed that a < a and b < b and hence we have neglected the product ab. If this is not the case, we do not really need to worry about errors in A. They are large. We can summarize with

It is convenient to use the fractional or relative error in quantities, such as the fractional error in a: a = (a/a). Dividing eq (2) by A = ab

Hence, we do a flying generalization and conclude that the relative errors add for multiplication. It can be shown the same is true for division. Convince yourself that for addition, the errors, NOT the relative errors add.

SUMMARY: For addition and subtraction, the error in the calculated quantity is the sum of the errors in the measured quantities. For multiplication and division, relative errors of the measured quantities add to give the relative error in the calculated quantity.

PART 2. Using the Vernier calipers, measure the three dimensions of your aluminum block. Record them here. H = ______, L = ______, and W = ______(Block #___). What is the smallest unit you can measure with these calipers? ______If you need help using the Vernier calipers, ask your laboratory instructor. Calculate the volume of this block and the estimated error in the volume.

Determine the mass of your block and calculate the density of the block and the estimated error in the density.

CONCLUSIONS: