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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I am using my Physics book, 0-13-060620-0. My roling object is a 15.25 oz can of Del Monte Lima Beans (full). My prop was a standard pencil about 50 mm away from the edge of the book. The book is 283 mm long and propped up 12 mm on the high end. The object rolled straight and smooth and it sped up as it traveled further down 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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These are my measurements from rolling left to right using the timer program:

2.359375

2.4375

2.1875

2.09375

2.125

Theses number are fairly close but there are two options for error when hitting the timer button. And error when starting and an error when it finishes rolling.

These are my number rolling from right to left:

2.203125

2.1875

2.203125

2.125

2.34375

These numbers are very similar to the opposite directions.

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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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From left to right the average was 126.7523324 mm/sec and from right to left the average speed was 128.0404734 mm/sec.

I believe that the accuracy may be fairly low since there are too many factor that could alter the readings, such as not hitting the button exactly at the right time.

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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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I put a mark halfway accros the book and timed from start to the mak and then to the end. This will give me speeds for two different sectiong and I will be able to see if the speed increases on the lower half.

My times for the first half were:

1.828125

1.421875

1.640625

1.625

1.59375

and I have an average speed of 87.80540975 mm/sec for the first section traveled

My time for the second half were:

0.703125

0.71875

0.75

0.65625

0.671875

and I have an average speed of 202.600875 mm/sec for the second section traveled.

This shows that the speed is increasing as the object travels further down the book.

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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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35 min

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

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This looks very good.