Phy 121
Your 'energy conversion 1' 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 optional message or comment: **
** How far and through what angle did the block displace on a single trial, with rubber band tension equal to the weight of two dominoes? **
1.12, 0
When the rubber band was stretched with a force of .38 N and released the domino was pulled toward the rubber band 1.12 cm.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of two dominoes: **
1.05, 8
.95, 12
1.05, 8
1.05, 8
1.1, 10
When the rubber band was stretched with .38 N and released the block was slung forward the number of cm indicated in the first column above and turned the corresponding number of degrees in the second column above. The block was pulled back enough to stretch the rubber band to a length of 6.55 cm, found to be a force of .38 N in a previous lab exercise, and then the distance measured from that point to the same point on the block after it came to rest.
** Rubber band lengths resulting in 5 cm, 10 cm and 15 cm slides: **
7.35, 8, N/A
The 15 cm slide was not possible due to the limitation of not stretching the rubber band more than 30% beyond its original length.
When the rubber band was stretched to a distance of 7.35 cm and released it propelled the block forward 5 cm. When the rubber band was stretched to a distance of 8 cm, it propelled the block forward 10 cm.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of four dominoes: **
3.45
3.55
3.45
3.50
3.55
When the rubber band was stretched with .76 N and released the block was slung forward the number of cm indicated in the lines above for each of 5 trials.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of six dominoes: **
5.55
5.6
5.68
5.7
5.85
When the rubber band was stretched with 1.14 N and released the block was slung forward the number of cm indicated in the lines above for each of 5 trials.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of eight dominoes: **
11.4
11.45
11.55
11.58
11.5
When the rubber band was stretched with 1.52 N and released the block was slung forward the number of cm indicated in the lines above for each of 5 trials.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of ten dominoes: **
I cannot stretch this rubber band to that length without exceeding 30% of its original length and did not do so in the rubber band calibration lab exercise.
That is the correct decision. Good judgement.
** Rubber band length, the number of dominoes supported at this length, the mean and the standard deviation of the sliding distance in cm, and the energy associated with the stretch, for each set of 5 trials: **
6.55, 2, 1.04, 0.05, .09
7.10, 4, 3.50, 0.05, .40
7.70, 6, 5.68, 0.11, .97
8.50, 8, 11.50, 0.07, 2.05
The last number in each line above indicates the energy, in Newton * cm, associated with that corresponding length of the rubber band. To calculate these, I took the corresponding energy found in the previous lab exercise for that interval and added it to the intervals before. For example, to find the energy associated with the rubber band being stretched to 8.5 cm, I took the previous intervals of .09 for two dominoes, .31 for 2-4 dominoes, .57 for 4-6 dominoes, and the 6-8 interval of 1.08 to get the total of 2.05 N * cm.
** Slope and vertical intercept of straight-line approximation to sliding distance vs. energy, units of slope and vertical intercept, description of the graph and closeness to line, any indication of curvature: **
5.33, .7
The slope of 5.33 given above is in cm per Newtons * cm and the vertical intercept is in cm.
The data points are fairly close to a best-fit straight line. Having only four points, it appears that a fairly decent curve may also fit.
** Lengths of first and second rubber band for (first-band) tensions supporting 2, 4, 6, 8 and 10 dominoes: **
4.79, 1.07
The slope of 4.79 given above is in cm per Newtons * cm and the vertical intercept is in cm.
The data points are fairly close to a best-fit straight line.
** Mean sliding distance and std dev for each set of 5 trials, using 2 rubber bands in series: **
6.55, 6.5
7.1, 6.8
7.7, 7.3
8.5, 7.8
This rubber band could not be stretched to support 10 dominoes.
** Slope and vertical intercept of straight-line approximation to sliding distance vs. energy, units of slope and vertical intercept, description of the graph and closeness to line, any indication of curvature: **
1.56 0.10
5.00 0.18
11.86 0.28
20.22 0.36
This rubber band could not be stretched to support 10 dominoes.
** 1-band sliding distance and 2-band sliding distance for each tension: **
1.04, 1.56
3.5, 5
5.68, 11.86
11.5, 20.22
The rubber bands could not be stretched to support 10 dominoes.
** Slope and vertical intercept of straight-line approximation to 2-band sliding distance vs. 1-band sliding distance, units of slope and vertical intercept, description of the graph and closeness to line, any indication of curvature: **
1.85, 0.95
The slope, 1.85, and vertical intercept, 0.95, given above are in cm.
A straight line seems to fit this data best which are clustered about the line.
** Discussion of two hypotheses: 1. The sliding distance is directly proportional to the amount of energy required to stretch the rubber band. 2. If two rubber bands are used the sliding distance is determined by the total amount of energy required to stretch them. **
This data supports the hypothesis that sliding distance is directly proportaional to the amount of energy required to stretch the rubber band fairly well.
** How long did it take you to complete this experiment? **
2.5 hours
** Optional additional comments and/or questions: **
&#Your work looks very good. Let me know if you have any questions. &#
&#Please see the following link for more extensive commentary on this lab. You should read over all the commentary and not anything relevant. Give special attention to any comments relevant to notes inserted into your posted work. If significant errors have occurred in your work, then subsequent results might be affected by those errors, and if so they should be corrected.
Expanded Commentary
Please respond by submitting a copy of this document by inserting revisions and/or self-critiques and/or questions as appropriate. Mark you insertions with #### and use the Submit Work Form. If a title has been suggested for the revision, use that title; otherwise use an appropriate title that will allow you to easily locate the posted response at your Access Page. &#