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initial timing experiment

PHY 231

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

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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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I used the book America's Greatest Golf Courses and I used a billiards ball as the object. I used a smaller book to prop it up. The ball rolled smoothly, although it did curve to the right a little as it was speeding down the ramp.

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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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1st interval 1.539063

2nd interval 1.4375

3rd interval 1.40625

4th interval 1.54128

I measured the book that I chose with a ruler. The book was 36.6cm in length. 1.48102325 was the average time that it took the ball to cover the 36.6cm stretch.

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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 ball is rolling at an average of 24.712643775173684815548979396508 cm/s. I believe that the average speed was probably within a few tenths of a second. I determined the average simply getting an average for the intervals and then dividing my distance traveled by my average duration.

The TIMER runs in intervals of approximately .015 seconds and this limits its precision. 24.7 cm/s is about as accurately as you can possibly determine the average velocity on this experiment. The remaining figures have no significance.

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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 an object approximately halfway down the length of the book to use as a reference point. Using the timer to get the duration between the starting point and halfway and then from halfway to the end of the book. From the starting point to halfway the ball typically took about 0.89912916s to reach halfway, and from halfway on to the end the ball typically took about 0.85354583s to make it to the end. This tells us that the ball is moving a little faster on the backstretch.

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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?

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

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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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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 TIMER runs in intervals of approximately .015 seconds and this limits its precision. 24.7 cm/s is about as accurately as you can possibly determine the average velocity on this experiment. The remaining figures have no significance.

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

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&#Good responses. See my notes and let me know if you have questions. &#