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: **
6.00 cm., 13.00 cm
7.00 cm
I obtained these numbers by placing my chain of rubber bands on a shelf so that it could hang freely and I could have both of my hands to work with. Then I placed my singly reduced ruler behind the first rubberband and measured it from two places subtracted the numbers and then multiplied that number by 1.6 cm to obtain the actual number of centimeters. I think my measurement is accurate to +- .05 centimeters.
** The basis for your uncertainty estimate: **
I think that I am unceratin to this extent because both the chain and my ruler that I am measuring with are slightly moving and I can't get either completely still. I think I am just being safe when I say .05cm uncertainty.
** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
6.00, 13.00
2.00, 10.00
4.00, 10.80
5.00, 12.30
End
7.00
8.00
6.80
7.30
** Distances between ends when supporting 2 dominoes **
7.00, 8.40, 7.20, 7.60
The above results were from rubberbands 1, 2, 3, 4 respectively with the weight of 2 dominoes.
** Lengths when supporting 4, 6, ... dominoes: **
7.30, 8.70, 7.60, 7.80 - 4
7.70, 8.90, 7.70, 7.90 - 6
7.90, 9.20, 7.80, 8.40 - 8
End
** Your table of force in Newtons vs. length in cm for all rubber bands **
7.00, 8.00, 6.80, 7.30 - .19
7.00, 8.40, 7.20, 7.60 - .38
7.30, 8.70, 7.60, 7.80 - .76
7.70, 8.90, 7.70, 7.90 - 1.14
7.90, 9.20, 7.80, 8.40 - 1.52
End
The above sequence of data is how each domino faired with the given number of dominoes (1,2,4,6,8 respectively going down). If you look at each of the columns this distinguishes each domino and how each did over the course of adding dominoes.
** Describe the graph of your first rubber band **
Increasing at an increasing rate throughout
Increasing at an increasing rate then beginning to increase at a decreasing rate
Increasing at an increasing rate throughout
Increasing at an increasing rate then increasing at a decreasing rate
** The tension force in your first rubber band at length 9.8 cm: **
My graph didn't extend to a point that reached 9.8 cm and seemed to never get there since it was increasing at an increasing rate.
** The length of your first rubber band when tension is 1.4 N: **
7.9 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: **
.35, .35, .70, 1.20, 1.40
.03, .03, .06, .06, .12
** 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: **
6.5, 7.6, 7.3, 7.8, 7.8
.5, .6, 0.0, .01, .01
** The typical error you estimate when predicting force for a given length from your graphs: **
I think I have more faith in the curve because I think that is somehow accounting for uncertainty. I think it would be +- .08 because that seems to be about the average for my curve to my actual numbers in the 2 examples above.
** The typical error you estimate when predicting length for a given force from your graphs: **
I think I would give an uncertainty value of about +-.5 because that seems to be the average of my discrepancies when looking at length.
** **
1 hour, 30 minutes
** **
&#Your work looks very good. Let me know if you have any questions. &#