Phy 121
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: **
(0, 14.67), 14.67. +-.1
** #$&* The basis for your uncertainty estimate: **
The measurements are made in .1 increments so that's my uncertainty.
** #$&* Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
(0, 14.67)
(0, 15.27)
End
14.67, 15.27
** #$&* Distances between ends when supporting 2 dominoes **
15.85cm
These results were from the weight of 2 dominoes.
** #$&* Lengths when supporting 4, 6, ... dominoes: **
17.45
4
17.76
6
18.34
8
19.35
10
END
** #$&* Your table of force in Newtons vs. length in cm for all rubber bands **
(14.67, .19)
(15.27, .38)
(15.85, .76)
(17.45, 1.52)
(17.76, 3.04)
(18.34, 6.08)
(19.35, 12.16)
A domino weights about .19 N. It would take over 60 dominoes to weigh 12.16 Newtons.
Your first few weights appear to correspond to the specified numbers of dominoes. The last few do not.
** #$&* Describe the graph of your first rubber band **
This graph is increasing at an increasing rate. The shapes of all six rubberbands are thin.
** #$&* The tension force in your first rubber band at length 9.8 cm: **
1.8
** #$&* The length of your first rubber band when tension is 1.4 N: **
9
** #$&* The forces at your observed lengths the 1st rubber band, as given by the curve, and the deviations of those curve-predicted lengths from the observed lengths: **
My lengths were a lot longer than these lengths. I guess I had larger rubberbands than I was supposed to have had.
This would depend on which ruler copy you used to measure the lengths. These lengths are certainly possible.
However you might also have used the thinner rubber bands.
** #$&* 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: **
8, 8.3, 8.6, 9.0, 9.4, 9.8, 10.2, 10.5, 10.9, 11.3
** #$&* The typical error you estimate when predicting force for a given length from your graphs: **
The values from the table. Those were found using exact data, not best-fit curves, or etc.
** #$&* The typical error you estimate when predicting length for a given force from your graphs: **
.05. because the increments are measured in .05
** **
30mins.
** **
&#Your work looks good. See my notes. Let me know if you have any questions. &#