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? **
.5 cm, 0 degrees
My first number is the number of centimeters that the block traveled after the rubberband was pulled back to 7 cm. The second number is the number of degrees that the block rotated. In this case it didnt rotate at all.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of two dominoes: **
1.8, 0
1.8, 0
1.8, 3
1.9, 3
1.9, 3
The first numbers are the amount of centimeters that block moved and the second numbers are the degrees that the block moved. The last few trials it began to move a little more than the first.
** Rubber band lengths resulting in 5 cm, 10 cm and 15 cm slides: **
7.7, 8.4, 9.1
These are the rubber band length I got for 5, 10, 15 cm traveled by the block.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of four dominoes: **
2.9, 5
3.0, 0
2.9, 0
2.9, 5
3.0, 5
The first numbers are the amount of centimeters that block moved and the second numbers are the degrees that the block moved.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of six dominoes: **
5.3, 0
5.3, 5
5.3, 5
5.3, 5
5.4, 5
5.4, 5
The first numbers are the amount of centimeters that block moved and the second numbers are the degrees that the block moved.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of eight dominoes: **
7.1, 5
7.4, 5
7.4, 5
7.3, 5
7.4, 5
The first numbers are the amount of centimeters that block moved and the second numbers are the degrees that the block moved.
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of ten dominoes: **
I didn't have data for 10 dominoes on the first rubber band because it exceeded the 30% barrier.
** 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: **
7cm, 2 dominoes, 1.84, .05477, .344
7.3cm, 4 dominoes, 2.94, .05477, .342
7.7cm, 6 dominoes, 5.38, .08367, .38
7.9cm, 8 dominoes, 7.32, .1304, .266
My energy is in joules and I got this from my data in the preceding experiment.
Your forces are on the order of a Newton or two, and rubber band stretches seem to be less than 1 cm. A 1 N force acting through 1 cm would yield only .01 Joules of work.
Also the energy associated with a 7.9 cm length would be considerably greater than that associated with a 7.3 cm length, not less.
Can you detail your calculations of the work/energy in your rubber band?
** 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: **
7.1, .75
slope units are in J per cm. vertical intercept is in cm.
My data points did not really lie close to my line at all. They don't really seem to form a line or a curve.
** Lengths of first and second rubber band for (first-band) tensions supporting 2, 4, 6, 8 and 10 dominoes: **
intercept = 1, slope = 8.57
Intercept has units of cm, slope has units of J per cm.
Again, my data points didn't really seem to go around the line. I had trouble drawing a straight line through the points.
** Mean sliding distance and std dev for each set of 5 trials, using 2 rubber bands in series: **
7.0, 7.9
7.3, 8.0
7.7, 8.5
7.9, 8.8
** 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: **
1.8, .1125
5.02, .2049
9.34, .1949
12.46, .3130
** 1-band sliding distance and 2-band sliding distance for each tension: **
1.84, 1.8
2.94, 5.02
5.38, 9.34
7.32, 12.46
** 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: **
2.4375, -2
Slope is in cm per cm. Vertical intercept is in cm.
My data points lie almost on a complete straight line and seem to indicate a straight line relationship.
** 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. **
I don't think my energy dadta was very accurate and I dont think that I ended up with the most accurate results. But I do think that the sliding distance is proportional to the amount of energy required. If the block slid further than the rubber band had to expel more energy by stretching to make is slide further.
** How long did it take you to complete this experiment? **
2 hours
** Optional additional comments and/or questions: **
Everything looks good except your rubber band energies, which are not of the right magnitude. See my note and please send me a revision with an explanation of how you obtained these energies. Indicate your revisions or explanations with &&&&.