rubber band calibration

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): **

Please respond relative to goal of C.

** first line ruler markings, distance in actual cm between ends, how obtained: **

3.00cm, 10.25cm

7.2cm

I took the difference of the 2 ruler measurements. The number in the second line is the stretched length of the rubber band with one domino in the bag. I marked the rubber band with 1 tick mark to indicate #1. I believe my measurement is accurate within +/-0.01cm.

** The basis for your uncertainty estimate: **

The basis for my estimate of the uncertainty of the length of the first rubber band is based on the precision of the ruler.

** Positions of the ends of each rubber band, actual lengths of each when the chain supports 1 domino: **

3.00cm, 10.25cm

3.00cm, 10.21cm

3.00cm, 10.48cm

3.00cm, 10.40cm

3.00cm, 10.44cm

3.00cm, 10.40cm

End

7.25cm, 7.21cm, 7.48cm, 7.40cm, 7.44cm, 7.40cm

I, II, III, IIII, IIIII, IIIIII

+-0.01cm

** Distances between ends when supporting 2 dominoes **

7.29cm, 7.27cm, 7.68cm, 7.62cm, 7.69cm, 7.55cm

These results were from the weight of 2 dominoes.

** Lengths when supporting 4, 6, ... dominoes: **

7.60cm, 7.51cm, 7.76cm, 7.70cm, 7.75cm, 7.50cm

4

7.71cm, 7.63cm, 7.99cm, 7.98cm, 7.95cm, 7.70cm

6

7.91cm, 7.80cm, 8.26cm, 8.22cm, 8.17cm, 7.96cm

8

8.14cm, 8.07cm, 8.48cm, 8.45cm, 8.40cm, 8.25cm

10

End

** Your table of force in Newtons vs. length in cm for all rubber bands **

7.25cm, 7.21cm, 7.48cm, 7.40cm, 0.19

7.29cm, 7.27cm, 7.68cm, 7.62cm, 0.38

7.60cm, 7.51cm, 7.76cm, 7.70cm, 0.76

7.71cm, 7.63cm, 7.99cm, 7.98cm, 1.14

7.91cm, 7.80cm, 8.26cm, 8.22cm, 1.52

8.14cm, 8.07cm, 8.48cm, 8.45cm, 1.90

End

The first column in each line represents the stretched length, in cm, of rubber band #1 supporting 1, 2, 4, 6, 8, and 10 dominoes. The next 3 columns represent the same for rubber bands 2, 3, and 4. The last column represents the downward force, in Newtons, exerted by gravity on 1, 2, 4, 6, 8, and 10 dominoes.

** Describe the graph of your first rubber band **

The graph is somewhat s- shaped or sigmoid. The graph increased at a decreasing rate, and then increased at an increasing rate.

The graph is somewhat s- shaped or sigmoid. The graph increased at a decreasing rate, and then increased at an increasing rate.

The graph is somewhat s- shaped or sigmoid. The graph increased at an increasing rate, and then increased at a decreasing rate.

The graph is somewhat s- shaped or sigmoid. The graph increased at a decreasing rate, and then increased at an increasing rate.

End

** The tension force in your first rubber band at length 9.8 cm: **

6.0N

** The length of your first rubber band when tension is 1.4 N: **

7.90cm

** 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: **

0.25, 0.33, 0.91, 1.08, 1.42, 1.86

+0.06, -0.05, +0.15, -0.06, -0.10, -0.04

** 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: **

7.23, 7.30, 7.50, 7.75, 7.97, 8.15

-0.02, +0.01, -0.10, +0.04, +0.06, +0.01

** The typical error you estimate when predicting force for a given length from your graphs: **

I have more faith in the values from the curve I just created because this line is very close to the best-fit line for the data. I think the uncertainty in the force for a given length would be +-0.10N because the estimates for force, read from the line, for the length measurements I obtained indicate a difference of -0.04N to +0.15N.

** The typical error you estimate when predicting length for a given force from your graphs: **

I think the uncertainty in the length for a given force would be +-0.05cm. This is because I obtained measurements of lengths for a given force from the graph ranging from -0.10cm to +0.06cm.

** **

2hrs.

** **

Please respond relative to goal of C.

&#Your work looks very good. Let me know if you have any questions. &#