initial timing experiment

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.

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Initial 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).

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.

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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Setup- In this experiment I used the Physics Sixth Edition textbook, positioned in a slight angle by a small book titled Symbiotic Planet written by Lynn Margulis. This was the smallest object I could find to position under the book for a slight angle. I used a plain ball point pen. The object rolled very smoothly in a straight line. It did speed up a small amount towards the end 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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Length of the book the object was rolled on, 43cm.

Length the object (ball point pen) actually rolled, 42 cm.

Height of book on flat surface, 5 cm

Height of book when angle was created, 6.75 cm

Time elapsed from released to rest, 2.296875, 2.546875, 2.078125, 2.234375, 2.171875, 2.1875.

Time elapsed from released to rest after 180 degree turn, 2.265625, 2.140625, 2.625, 2.046875, 2.578125, 2.5625

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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 object was moving 0.1817 m/s on average. The objects average speed was determined by averaging the amount of time it took for each trial. That average was then paired with the distance it had to travel, which was 42 cm. Thus on average the object rolled 42 cm per 2.311198 seconds. This was then converted to m/s using a simple conversion. This experiment was done with the best possible accuracy, however, we must take into consideration human error.

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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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In this experiment I did two different sets of data to prove the object was in fact speeding up and compared it to the original set of data. I measured six times, the amount of time it took for the object to travel from rest at the top of the book, to the middle of the book. This object rolled 21 cm each time. I then took measurement from letting the object go at the top of the book to 3/4 of the book. This time each measurement was for a total of 31.5 cm.

DATA

From rest to middle of book, 1.046875, 1.234375, 1.140625, 1.203125, 1.296875, 1.265625

From rest to 3/4 of book, 1.71875, 1.828125, 1.703125, 1.750, 1.7125, 1.82815

I then compared the average amount of time between the measurements. From the top of the book to the middle of the book it averaged 1.1976 seconds. From the second set of measurements I determined an average of 0.55 seconds. Thus, these calculations show the object speeding up by almost 50%.

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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: 

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45 minutes

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You may add optional comments and/or questions in the box below.

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Very good work. Let me know if you have questions. &#