Phy 201
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? **
4.4,0
The first number is in cm and it is the distance the block moved from release at rubberband tension 7.55cmThe second number is how far the block moved off of its straight line in degrees
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of two dominoes: **
4.3,0
4.5,0
4.6,0
4.5,0
4.8,0
These numbers are the results of performing the same test above but doing five times
** Rubber band lengths resulting in 5 cm, 10 cm and 15 cm slides: **
7.9,8.4,8.9
Starting from left to right these are the rubberband lengths in cm for the block to go 5cm ,10cm,and 15cm
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of four dominoes: **
5.5,0
5.6,0
5.6,0
6.0,0
5.9,0
These are the block distance in cm of my 5 trials for the stretch of the rubberband at 4 dominos which is 7.8cm
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of six dominoes: **
7.4,0
7.5,0
7.5,0
7.7,0
7.9,0
These are the block distance in cm of my 5 trials for the stretch of the rubberband at 6 dominos which is 8.05cm
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of eight dominoes: **
9.1,0
9.1,0
8.8,0
9.3,0
9.4,0
These are the block distance in cm of my 5 trials for the stretch of the rubberband at 8 dominos which is 8.2cm
** 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of ten dominoes: **
10.4,0
10.6,0
10.9,0
11.1,0
11.1,0
These are the block distance in cm of my 5 trials for the stretch of the rubberband at 10 dominos which is 8.4cm
** 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: **
7.55,2,4.54,.1817,1.8
7.8,4,5.72,.2168,4.3
8.05,6,7.6,.2,8.7
8.2,8,9.14,.2302,13.9
8.4,10,10.82,.3114,20.6
The energy is in N*cm.The rows from top to bottom are the 2d,4d,6d,8d,10d, stretches. From left to right we have rubberband length,#dominos, mean, standard deviation,energy. The rubber band legth is from my rubberband calibration exp.and the mean and standard deviation is from the data program where I entered the 5 trial block distances. And the energy I got from the distance the block travel * the newtons per stretch of rubberband. We know the newtons from the rubberband calibration of.38 for 2dominos,.76 for dominos,etc..So for a stretch of 2dominos at 7.55cm we have .38newtons and the distance the block traveled
The stretch from 8.2 cm to 8.4 cm happens against an average attention force equivalent to the weight of 9 dominoes, or about 1.7 Newtons. The stretch for this interval is .2 cm, so the energy would be about 1.7 N * .002 m = .0034 Joules, or about .34 N * cm.
The average force between 7.55 cm and 8.4 cm appears to be around the weight of 5 dominoes, or about .95 N; multiplied by the .85 cm displacement, we get about .8 N * cm.
The work associated with each interval should be calculated and accumulated to get a reasonably accurate total for each pullback distance.
** 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: **
5,11.2
cm
The data point are pretty close to the line, two above the ine and three below. I believe we do have a little curvature.I believe it is at a downward concavity
** Lengths of first and second rubber band for (first-band) tensions supporting 2, 4, 6, 8 and 10 dominoes: **
4,22.5
cm
These data point were alittle further from the line with three above the line and two below the line.
The curvature on this on this one had a downward concavity throught the first four points then started and upwards curvature between the fourth and fifth points
** Mean sliding distance and std dev for each set of 5 trials, using 2 rubber bands in series: **
7.55,7.6
7.8,7.8
8.05,8.0
8.2,8.2
8.4,8.3
** 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: **
3.62,.2280
8.74,.2408
13.98,.3834
16.28,.2588
21.24,.3647
** 1-band sliding distance and 2-band sliding distance for each tension: **
4.54,3.62
5.72,8.74
7.6,13.98
9.14,16.28
10.82,21.24
** 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: **
2.5,12
This is reasonably consistent with the expectation that the sliding distance for two rubber bands in series is about double that expected for one rubber band.
cm
All of them are right against the line od very close to it. This line is straighter then the others. Could be straight
** 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. **
Seems to be true. The further I stretched the rubberband the the more consistant it got as far as the block doubling its distance. I guess since the rubberbands were not exactly the same and at the smaller stretches it made a different in my numbers. Maybe a little more slack in the whole system
** How long did it take you to complete this experiment? **
3hrs
** Optional additional comments and/or questions: **
All data appear to be good and most of the analysis is correct. However you do not appear to have correctly calculated the energy of the stretched rubber bands.
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