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: **
2.0cm, 9.8cm
7.8cm
The numbers in the second line were obtained by subtracting the ending measurement from the beginning measurement which indicate the length of the rubber band that has been stretched by one domino. This rubber band had 1 black mark on it. I believe my measurements are accurate to +- .20 cm
** The basis for your uncertainty estimate: **
My uncertainty is based on my accuracy. It's hard to hold the ruler perfectly still and have the chain be perfectly still when measuring. It takes a couple of tries to get everything as close as possible.
** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
2 cm, 9.8 cm
2 cm, 10 cm
2 cm, 9.4 cm
2 cm, 9.8 cm
2 cm, 9.7 cm
End
7.8cm
8 cm
7.4 cm
7.8 cm
7.7 cm
Each rubber band has a number of black marks on it. The top one has 1, next has 2, next has 3, etc.
The uncertainty is +-.20cm.
** Distances between ends when supporting 2 dominoes **
8.1cm
7.8cm
7.9cm
7.6cm
8.1cm
8.3cm
These were the results from the weight of 2 dominoes
** Lengths when supporting 4, 6, ... dominoes: **
8.3cm, 7.9cm, 8.0cm, 7.8cm, 8.2cm, 8.1cm
4
8.4cm, 8.2cm, 8.0cm, 8.0cm, 8.4cm, 8.2cm
6
8.6cm, 8.3cm, 8.2cm, 8.2cm, 8.5cm, 8.3cm
8
8.8cm, 8.5cm, 8.6cm, 8.4cm, 8.7cm, 8.5cm
10
End
** Your table of force in Newtons vs. length in cm for all rubber bands **
7.8cm, 7.8cm, 8.0cm, 7.4cm, .19N
8.1cm, 7.8cm, 7.9cm, 7.9cm, .38N
8.3cm, 7.9cm, 8.0cm, 7.8cm, .76N
8.4cm, 8.2cm, 8.0cm, 8.0cm. 1.14N
8.6cm, 8.3cm, 8.2cm, 8.2cm, 1.52N
8.8cm, 8.5cm, 8.6cm, 8.4cm, 1.9N
End
The first four numbers in each line are the lengths in cm of the rubber bands when corresponding to the number of Newtons from the fifth number.
** Describe the graph of your first rubber band **
Rubber Band #1 increases at a constant rate.
Rubber Band #2 seems to increase at a average constant rate.
Rubber Band #3 length seems to stay fairly constant until 1.5N are against it and then the length begins to increase at an increasing rate.
Rubber Band #4 seems to increase at a constant rate.
Rubber Band #5 seems to increase at a constant rate.
Rubber Band #6 seems to be the one with the most inconsistency. Generally the graph increases at a constant rate.
End
** The tension force in your first rubber band at length 9.8 cm: **
5.2 N
** The length of your first rubber band when tension is 1.4 N: **
8.4 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: **
.19N, .55N, .82N, 1.05N, 1.48N, 1.88N
.38N total difference
** 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: **
7.8cm, 8.09 cm, 8.3 cm. 8.42 cm, 8.62 cm, 8.78 cm
.07cm difference
** The typical error you estimate when predicting force for a given length from your graphs: **
I have a little more faith in the curve because the points give us an approximate measurement. By looking at all of the points together, it gives us a trend. The uncertainty of force would be +- .2N because I averaged a difference of .38N so .2N + or - would allow me a total of .4N difference which is close to the .38N difference in the curve.
** The typical error you estimate when predicting length for a given force from your graphs: **
The length uncertainty was closer than the force. My length difference was a total of .07cm so and would assume that +-.1cm would give an average uncertainty.
** **
1.75 hrs.
** **
&#Your work looks very good. Let me know if you have any questions. &#