Your 'initial timing experiment' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** template formInitial Timing Experiment
You may enter any message or comment you wish in the box below:
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In this experiment you will use the TIMER program, a hardcover book, a cylinder or some other object that will roll along the book in a relatively straight line, and a ruler or the equivalent (if you don't have one, note the RULERS link on the Assignments page).
- The book's cover should be straight and unbent.
- The object should roll fairly smoothly.
Place the book on a flat level tabletop. You will prop one end of the book up a little bit, so that when it is released the object will roll without your assistance, gradually speeding up, from the propped-up end to the lower end. However don't prop the end up too much. It should take at least two seconds for the ball to roll down the length of the book when it is released from rest.
- Using the TIMER program determine how long it takes the ball to roll from one end of the ramp to the other, when released from rest. Time the object's motion at least five times.
- Determine how far the object actually travels as it rolls from one end to the other.
- Determine how much higher one end of the book was than the other, and how far it is from one end to the other.
Then reverse the direction of the book on the tabletop, rotating the book and its prop 180 degrees so that the ball will roll in exactly the opposite direction. Repeat your measurements.
In the box below describe your setup, being as specific as possible about the book used (title, ISBN) and the object being used (e.g., a solid glass marble, a small can of tomato paste (full or empty?), a ball-point pen), and what you used to prop the object up (be as specific as possible). Also describe how well the object rolled--did it roll smoothly, did it speed up and slow down, did it roll in a straight line or did its direction change somewhat?
Note: Don't trust this form. Compose your answer in Notepad or a word processor, saving it every few minutes, then copy and paste it into the box. Power could surge, your computer could malfunction, in any of a number of ways the work you put into this form could be lost. Compose it elsewhere and keep a copy.
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used the University Physics w/Modern Physics Young 11th Edition ISBN: 9780805386844 which has a length of 26cm. I am using a 184g can of Valutime Mushroom Stems & Pieces to roll down the book. It has a diameter of 6.5cm. At the end of the book I have a metal envelope holder at the end of the ramp that is set to catch the can and make an audible noise when it hits. The envolpe holder is positioned to be 3.25 cm away from the end of the book so that the can will roll the length of the 26cm book. The start for the can is designed to start it halfway off the edge of the book.
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In the box below report your data. State exactly what was measured, how it was measured, how accurately you believe it was measured and of course what the measurements were. Try to organize your report so the reader can easily scan your data and see any patterns that might occur.
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I measured the length of the book to be 26cm, so the times that are recorded below reflect movement through those 26 cm. I am confident that the measurements were fairly accurate due to not watching the can hit (and possibly anticipating the hit), but by hearing it.
Measured in seconds:
2.475
2.297
2.516
2.451
2.344
Reverse:
2.578
2.643
2.844
2.469
2.344
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Using your data determine how fast the object was moving, on the average, as it rolled down the incline. Estimate how accurately you believe you were able to determine the object's average speed, and give the best reasons you can for your estimate of the accuracy.
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The average time of the first data points is 2.417s
The average time of the second data points is 2.576s
The length of the book is 26cm, so the can was traveling 26cm/2.417s = 10.757cm/s
In the second run, the speed was 26cm/2.576s = 10.0932cm/s
I believe that the estimate is fairly accurate. I do feel that the can may have gotten a little dented through hitting the envelope holder and may have hindered the performance in the second run.
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Devise and concuct an experiment to determine whether or not the object is speeding up as it rolls down the incline. If you have set the experiment up as indicated, it should seem pretty obvious that the object is in fact speeding up. But figure out a way to use actual measurements to support your belief.
Explain how you designed and conducted your experiment, give your data and explain how your data support your conclusions.
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At the start of each run, the speed of the object is 0cm/s. Over the course of the run, the can reaches an average speed of around 10cm/s. Would this not be a gain in speed?
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Your instructor is trying to gauge the typical time spent by students on these experiments. Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades:
- Approximately how long did it take you to complete this experiment?
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About an hour.
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You may add optional comments and/or questions in the box below.
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I am still a bit unsure of what measurements that I could take to show an increase in speed other than what was done here.
You could, for example, time the object down the first 5 cm, then down the first 10 cm, etc., and show that the average velocity increases with the distance down the incline.
What more direct approach might you use?.
In any case, good work.