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? **
16.3 cm, 10 degrees
I found the distance traveled by the domino stack by measuring from the center point that was first marked before releasing the domino and then measuring to the center point of the domino stack after it was released. I made an estimate for the distance that the stack rotated before it came to a rest. This was relatively easy to do from the marks we made on our paper when marking where the domino came to a stop.
** #$&* 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of two dominoes: **
24.2, 5 degrees
23.2, 20 degrees
26.5, 15 degrees
24.4, 20 degrees
28cm, 3 degrees
** #$&* Rubber band lengths resulting in 5 cm, 10 cm and 15 cm slides: **
N/A, 8.5 cm, 9.3cm
I was unable to get the domino stack to only travel 5cm. It would always move further than that.
The numbers provided above are the lengths that the rubberband was stretched to allow the domino stack to move a certain distance
** #$&* 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of four dominoes: **
24.4cm, 10 degrees
29.2cm, 10 degrees
22.7cm, 15 degrees
23.7 cm, 5 degrees
21.7, 15 degrees
The numbers provided above are the lengths that the rubberband was stretched to allow the domino stack to move a certain distance.
** #$&* 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of six dominoes: **
27.1cm, 15 degrees
25.8cm, 25 degrees
26.1cm, 20 degrees
27.4cm, 15 degrees
27.9cm,10 degrees
The numbers provided above are the lengths that the rubberband was stretched to allow the domino stack to move a certain distance.
** #$&* 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of eight dominoes: **
35.2cm, 25 degrees
35.9cm, 30 degrees
38.7cm, 30 degrees
44.8cm, 15 degrees
36.7cm, 10 degrees
The numbers provided above are the lengths that the rubberband was stretched to allow the domino stack to move a certain distance.
** #$&* 5 trials, distance in cm then rotation in degrees, with rubber band tension equal to the weight of ten dominoes: **
34.2cm, 20 degrees
37.1 cm, 15 degrees
35.4cm, 25 degrees
39.8cm, 30 degrees
40.2cm, 25 degrees
The numbers provided above are the lengths that the rubberband was stretched to allow the domino stack to move a certain distance.
** #$&* Rubber band length, the number of dominoes supported at this length, the mean and the standard deviation of the sliding distance in cm, and the energy associated with the stretch, for each set of 5 trials: **
11.4, 2, 25.26, , 1.946, 2.28 N cm
11.5, 4, 24.34, 2.902, 2.3N cm
11.2, 6, 26.86, .8849, 2.8N cm
11.7, 8, 38.26, 3.884, 2.925N cm
11.5, 10, 37.34, 2.642, 2.875 N cm
My first number in each line has a unit of cm, the second number has a unit of cm, the 3rd number is dominoes, the 4th number is the standard deviation and the final answer is the energy and is in N cm. I found my energy by taking the N for each length of the specific rubberband and multiplying it by the given length.
Units are right, but when the rubber band supports 10 dominoes it's longer than when it supports 2 dominoes. Your lengths don't show the expected (and inescapable) progression.
** #$&* 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: **
16, 1.6
N , cm
My data points somewhat cluster closely around the best fit line. Three of my points are sitting just above the best fit line. Two of my other points are higher than the three points that are just above the best fit line-There is not enough room between both sets of points to place the best fit line in between
It looks as though this graph could have a downward concavity.
** #$&* Lengths of first and second rubber band for (first-band) tensions supporting 2, 4, 6, 8 and 10 dominoes: **
32, 2.6
N, cm
This best fit line fits very closely to my data points. Each one lines directly next to the line with none extending super far above or below the line.
It appears as though this graph has an upward concavity.
** #$&* Mean sliding distance and std dev for each set of 5 trials, using 2 rubber bands in series: **
11.4, 11.4
11.5, 11.5
11.2, 11.2
11.7,11.7
11.5, 11.5
I realize that my lengths are the same for each band, but when stretching my first band to its proper length, my second band was also stretched the exact same distance.
** #$&* Slope and vertical intercept of straight-line approximation to sliding distance vs. energy, units of slope and vertical intercept, description of the graph and closeness to line, any indication of curvature: **
37.48, 1.370
46.1, 1.930
53.5, 3.012
77.26, 2.223
** 1-band sliding distance and 2-band sliding distance for each tension: **
25.26, 31. 53
24.34, 37.48
26.86, 46.1
38.26, 53.5
37.34, 72.76
** #$&* 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, 12.5
cm
The points on the graph are located above and below the best fit line. The look as though it could indicate a curved graph.
The behavior of the curve changes several times. At first it looks as though it is decreasing at an increasing rate and then it increases at an increasing rate and once again increases at a decreasing rate.
** #$&* Discussion of two hypotheses: 1. The sliding distance is directly proportional to the amount of energy required to stretch the rubber band. 2. If two rubber bands are used the sliding distance is determined by the total amount of energy required to stretch them. **
I think that the experiment does support the hypotheses that if two rubber bands are used that the sliding distance is determined by the total amount of energy that is required to stretch the bands. If we require more work to pull the dominoes back then it only makes sense that the potential energy that the dominoes has will increase and be converted over to our kinetic energy. More pull back equals a further distance that our domino stack travels.
** #$&* How long did it take you to complete this experiment? **
2-3 hours I took some breaks in between so it fell somewhere in that range.
** #$&* Optional additional comments and/or questions: **
Can you clarify my one question about your reported rubber band lengths?