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, 25.8
7.41
I subtract 10 from 25.4 to get the distance in cm on the doubly reduced ruler. Divide this number by 2.131 which was the number of cms on the reduced ruler that I determined previously are needed to make up one actual cm. The rubber band is marked with one green dot. I estimate that the measurement is accurate to +-0.06cm.
** The basis for your uncertainty estimate: **
I calculated the standard deviation of my doubly reduced ruler using a sample of three out of the original 6 measurements obtained in the paper ruler calibration.
** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
10, 25.8
10, 25.8
10, 25.4
10, 25.9
10, 25.4
10, 25.5
End
7.41, 7.41, 7.23, 7.46, 7.23, 7.27
1,2,3,4,5,6
+-0.06
** Distances between ends when supporting 2 dominoes **
7.6, 7.6, 7.41, 7.56, 7.41, 7.46
two dominoes
** Lengths when supporting 4, 6, ... dominoes: **
7.84, 7.79, 7.6, 7.84, 7.7, 7.65
4
7.98, 8.02, 7.84, 7.98, 7.84, 7.84
6
8.21, 8.31, 8.02, 8.31, 8.12, 8.12
8
8.54, 8.59, 8.35, 8.59, 8.35, 8.4
10
** Your table of force in Newtons vs. length in cm for all rubber bands **
7.41, 7.41, 7.23, 7.46, 7.23, 7.27, 0.19
7.6, 7.6, 7.41, 7.56, 7.41, 7.46, 0.38
7.84, 7.79, 7.6, 7.84, 7.7, 7.65, 0.76
7.98, 8.02, 7.84, 7.98, 7.84, 7.84, 1.14
8.21, 8.31, 8.02, 8.31, 8.12, 8.12, 1.52
8.54, 8.59, 8.35, 8.59, 8.35, 8.4, 1.9
length in cm of rubber band #1, #2, #3, #4, #5, #6, downward force exerted calculated by # of dominoes multipied by 0.19
** Describe the graph of your first rubber band **
Increasing at a fairly constant rate, increasing at an increasing rate, increasing at a decreasing rate, increasing at a fairly constant rate
** The tension force in your first rubber band at length 9.8 cm: **
9.8 cm is way off of my graph. Mine goes up to 8.6 cm and 2.0 Newtons.
** The length of your first rubber band when tension is 1.4 N: **
8.11cm
** 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: **
0.2, 0.4, 0.75, 1.1, 1.54, 1.88
0.01, 0.02, 0.01, 0.04, 0.02, 0.02
** 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: **
7.38,7.58, 7.85, 8.02, 8.2, 8.6
0.03,0.02, 0.01, 0.04, 0.01, 0.06
** The typical error you estimate when predicting force for a given length from your graphs: **
I have more faith in the curve because it is very similar to the curves of all the other graphs for the other rubberbands.
I think the uncertainty would be +- 0.02. I found the mean of the differences between the values I obtained measuring the rubberbands and the values I obatained using the curve to estimate force.
** The typical error you estimate when predicting length for a given force from your graphs: **
+- 0.03. I found the mean of the differences between the values I obtained measuring the rubberbands and the values I obtained using the curve to estimate length.
** **
2hours 30 mins to complete experiment and calculations, 1 hour to draw the graphs and type it up. Total 3 hr 30 min
** **
&#Very good responses. Let me know if you have questions. &#