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 couldn’t really figure out the TIMER program

OK- the first experiment I used a safety plug outlet cover, 2cm in height and 3.5cm width to prop the book up. You can find what I am talking about in the baby section of most discount department stores, (Target, WalMart etc) I used a film canister with a full roll of film, and used a smaller book (‘Surviving the Applewhites’; ISBN 0-06-441044-7) and I realized that book was really too small to do the experiment with; I did it five times; The canister rolled quickly each time. The distance from the floor to the highest point on the smaller book was approx. 4cm; from the bottom to the top of the book was 1cm. So, I switched to a bigger book the class textbook ‘Physics’ ISBN0-13-060620-0. (6cm) when I used the bigger book it was really interesting, because at first the film canister kind of went slowly, then really took off when it hit a certain point. That was kind of cool. It also curved off the right a little bit no matter which way the book was turned, indicating that the film was heavier on one side than the other.

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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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The first experiment here are the results:

Text1

1 0 0

2 .9179688 .9179688

3 89.31641 88.39844

4 96.73828 7.421875

5 102.3555 5.617188

6 107.3516 4.996094

I don’t think I even understand what they mean. Here are the results from the 2nd book:

Text1

1 0 0

2 2.101563 2.101563

3 8.203125 6.101563

4 11.4375 3.234375

5 24.56641 13.12891

6 25.98828 1.421875

7 29.99219 4.003906

8 31.99609 2.003906

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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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Again, I am not sure how to really interpret the little TIMER program, so I just used the 2nd hand clock method. When I set it up that way, I came up with an average roll of 2.1 seconds.

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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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Well, the nice thing about this part was I didn’t have to do this because it was very obvious that as the object rolled, it gained more potential energy. The steeper the incline, the more energy gained. However, if it hadn’t been so obvious, I would have marked sections of the textbook, then using a timer, clocked each measured portion separately and taking three trials each, to determine the portion of the book where the speed was the greatest; or where the most potential energy was being gained and the fastest kinetic energy was being displayed.

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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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an hour

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

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Still trying to figure out the TIMER program.