Your 'rubber band calibration' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** Your initial comment (if any): **
** first line ruler markings, distance in actual cm between ends, how obtained: **
10, 20
10 cm
I obtained the number in the second line by subtracting the 2nd number from the 1st number in the first line. This is how far the rubber band is stretched with only 1 domino in the bag at the end of the rubberband / hook chain. I believe my measurement is accurate to +- .1 of the measurement.
** The basis for your uncertainty estimate: **
because it is a little hard to measure the rubber band completely accurate while it is hanging due to movement.
** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
10, 19.5
10, 19.5
10, 9
End
9.5, 9.5, 9
again, the uncertanty of my measurements would be between +- .1 and +- .2
** Distances between ends when supporting 2 dominoes **
10.5, 10.3, 10.5, 10.0
These are the results from the weight of two dominoes
** Lengths when supporting 4, 6, ... dominoes: **
10.9, 10.9, 10.8, 10.6
4
11.5, 11.8, 11.8, 11.3
6
12.7, 12.8, 13.0, 12.4
8
13.5, 13.5, 14.0, 13.1
10
End
** Your table of force in Newtons vs. length in cm for all rubber bands **
10.0, 9.5, 9.5, 9.0 - .19
10.5, 10.3, 10.5, 10.0 - .38
10.9, 10.9, 10.8, 10.6 - .76
11.5, 11.8, 11.8, 11.3 - 1.14
12.7, 12.8, 13.0, 12.4 - 1.52
13.5, 13.5, 14.0, 13.1 - 1.9
End
Each of the first four columns are the measurements recorded from each rubber band in the same order. These measurements are measured in cm. The final column, after the dash, indicates the weight of the bag of dominoes, in N.
** Describe the graph of your first rubber band **
1. Increasing at an Increasing rate, and then increasing at a decreasing rate
2. Increasing at an increasing rate, then increasing at a decreasing rate
3. increasing at an increasing rate, then at a decreasing rate
4. increasing at an increasing rate, then at a decreasing rate
End
** The tension force in your first rubber band at length 9.8 cm: **
** The length of your first rubber band when tension is 1.4 N: **
11.8 cm
** The forces at your observed lengths the 1st rubber band, as given by the curve, and the deviations of those curve-predicted lengths from the observed lengths: **
.2, .42, .55, 1.08, 1.55, 1.85
The actual weight supported by these rubber bands differs from the estimated curve by about +- .2
** The lengths predicted for forces .19 N, .38 N, .76 N, 1.14 N, etc. by the curve for your first rubber band; the deviations of your actual observations from these predictions: **
10.0, 10.3, 10.9, 11.4, 12.6, 13.2
The actual length of these rubber bands observed differs from the estimated curve by about +- .4 at the most.
** The typical error you estimate when predicting force for a given length from your graphs: **
-I personally have more faith in the values of the curve when looking at numerous groups of data, because the curve msot resemebles each other, rather than the different measurements and points, which could and do have human error.
-I do not think that my data would give a result with +- .12N or +- .03N of uncertainty just because I am knew at these kinds of measurements, and would not use my measurements when thinking of a more serious solution.
** The typical error you estimate when predicting length for a given force from your graphs: **
Again, I do not think I would be able to estimate the length with the given uncertainty, just because I do not trust my human eye and measuremetns for a more serious task.
** **
45 min
** **
&#Very good responses. Let me know if you have questions. &#