Phy 201
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: **
20.00, 31.20
11.20
I got these numbers using the singly reduced rulers. I think my measurement is accurate to the .1 cm. The second number means that the first rubber band is 11.2cm long with the rubber band in the bag. The first rubber band is marked with a 1.
** The basis for your uncertainty estimate: **
My ruler is marked to mm, so anything smaller than that i would have to guess and would be uncertain.
** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **
20.00, 31.20
20.00, 31.20
20.00, 31.50
20.00, 30.90
20.00, 31.10
20.00, 31.50
end
11.20, 11.20, 11.50, 10.9, 11.10, 11.50
Each of my rubber bands is marked with a 1-6 in order. The frist number corresponds to the band marked one and the second to the 2, and so on.
** Distances between ends when supporting 2 dominoes **
11.61, 11.45, 11.75, 11.25, 11.50. 11.70
This is with two dominos
** Lengths when supporting 4, 6, ... dominoes: **
11.75, 11.60, 12.00, 11.41, 11.70, 11.95
4
12.20, 12.05, 12.45, 11.95, 11.97, 12.50
6
12.40, 12.25, 12.85, 12.10, 12.35, 12.85
8
12.80, 12.76, 13.00, 12.40, 12.70, 13.00
10
13.23, 12.90, 13.24, 12.72, 13.01, 13.43
12
13.60, 13.24, 13.65, 12.90, 13.34, 13.87
14
Out of dominoes, end
** Your table of force in Newtons vs. length in cm for all rubber bands **
11.20, 11.20, 11.50, 10.9, 11.10, 11.50, .19N
11.61, 11.45, 11.75, 11.25, 11.50. 11.70, .38N
11.75, 11.60, 12.00, 11.41, 11.70, 11.95, .76N
12.20, 12.05, 12.45, 11.95, 11.97, 12.50, 1.14N
12.40, 12.25, 12.85, 12.10, 12.35, 12.85, 1.52N
12.80, 12.76, 13.00, 12.40, 12.70, 13.00, 1.9N
13.23, 12.90, 13.24, 12.72, 13.01, 13.43, 2.28N
13.60, 13.24, 13.65, 12.90, 13.34, 13.87, 2.66N
End
Each column represents a rubber band (1-6) in order ending with the force in N that resulted in the length changes.
** Describe the graph of your first rubber band **
My curves seem to be increasing at either a constant rate or slightly increasing rate. Length was placed on the x axis (in cm) and F in N was placed on the y axis. Initially, the graphs definitely increase at an increasing rate, but they may slightly level off, which is why it may be constant on average.
First:increasing at a constant rate
second: increasing at a constant rate
third: curve, usually constant but decreasing rate in the middle
fourth: increasing at a constant rate
fifth: constant rate
sixth:increasing rate, then constant probably constant with error
end
** The tension force in your first rubber band at length 9.8 cm: **
0.5N
** The length of your first rubber band when tension is 1.4 N: **
12.30cm
** 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: **
0.19, 0.4, .60, 1.3, 1.6, 1.85, 2.2, 2.6
0, .02, .16, .16, .08, .05, .08, .06
** 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: **
11.2, 11.60, 11.90, 12.10, 12.60, 12.71, 13.15, 13.60
0, .01, .15, .10, .20, .09, .08, .10
** The typical error you estimate when predicting force for a given length from your graphs: **
I have more faith is the values from the curve. There is error in measurements and in the ruler i was using in addition to human error. The curve is the best fit line and is a way to balance out these errors.
** The typical error you estimate when predicting length for a given force from your graphs: **
I would say it would by +-.05cm. We eliminate some of the error by making a best fit line for the data so the error should be smaller. In addition, the differences in actual N and the graph show little variation.
** **
2 hours
** **
9.8 would have shown negative force on my rubber bands, as they were initially longer then this. Instead I estimated for 11.8 which shows up on all of my graphs. Sorry if this is a problem.
No problem.
Good data, good work.