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.
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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?
2.5, 2
5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of two dominoes:
4.0,5
2.5, 20
2.6,2
1.5,2
2.0,0
Rubber band lengths resulting in 5 cm, 10 cm and 15 cm slides:
8,9,10
10cm is over the 9.36 limit of 30% restriction.
5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of four dominoes:
2.1,4
2.4,0
2.5,2
2.1,0
2.0,5
5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of six dominoes:
2.4,3
2.4,0
2.5,0
2.9,5
2.7,0
5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of eight dominoes:
4.3,3
4.1,10
4.5,10
4.7,0
5.2,10
5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of ten dominoes:
9.2,0
10.2,10
11.0,20
11.5,10
12.0,25
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:
7.55,2,2.52,.9365,.9576
7.80,4,2.22,.2168,1.6872
8.02,6,2.58,.2168,2.9412
8.24,8,4.56,.4219,6.9312
8.51,10,10.78,1.105,20.482
It isn't clear how you are getting the energies you report here. Can you send me a copy of the following and the details of your energy calculation?
Note that the energy required to stretch the rubber band is equal to the average force exerted by the rubber band force, from the length at which the rubber band first starts exerting a force to the length of the stretch. This average force applies only over the distance through which the rubber band exerts its force, i.e., over the distance between these two positions.
One common error made at this point is to multiply the force exerted by the rubber band by the sliding distance. The rubber band does not exert its force through the sliding distance, but only through the pullback distance.
Another common error is to use the force of the rubber band at its maximum pullback distance. The rubber band only exerts this force at the maximum pullback distance; the force decreases to 0 as the rubber band returns to its original length. The work done by the rubber band is equal to average force * the distance through which the force is exerted.
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:
2.2319,-3.5143
1/N, N*cm
The points are fairly clustered, they seem to indicate a straight-line relationship.
There is no apparent curvature.
Lengths of first and second rubber band for (first-band) tensions supporting 2, 4, 6, 8 and 10 dominoes:
3.9668, -10.938
1/N, N*cm
The first points cluster well around the line, but the last two are further from the line. It is a straight line relationship
Mean sliding distance and std dev for each set of 5 trials, using 2 rubber bands in series:
2,7.55,7.4
4,7.80,7.5
6,8.02,8.1
8,8.24,8.2
10,8.51,8.5
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:
3.02,.4207
4.58,.9576
5.54,.7197
20.24,1.433
27, 2.168
1-band sliding distance and 2-band sliding distance for each tension:
2.52,3.02
2.22,4.58
2.58,5.54
4.56,20.24
10.78,27.00
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:
2.714,-.2237
no units,cm
the data points do not cluster around the line well, they indicate some curvature
the curvature is concave down
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.
yes, because the first two graphs showed a linear relationship with N*cm vs cm.
How long did it take you to complete this experiment?
3 hrs
Optional additional comments and/or questions:
Overall you have good data; however I believe your energy calculations were on at least some trials incorrect. Submit a copy of my note with a copy of your relevant data and an explanation of how you calculated those energies.