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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For my experiment I used a full coke can of 355ml, 1 grey 1inch binder at 32deg of incline and a distence of 25.5 cm. The object was rolled from the high edge to the bottom of the binder. The can rolled smoothly and in a straight path due to the midpoint release of the can. The can speed up as it rolled down the incline and onto the table.

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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 can's distance was measured at 25.5cm. From point 0 to 25.5 mark the can was rolled 5 times down the inlcline.

Att 1: 2.7187 sec.

Att 2: 2.3460 sec.

Att 3: 2.8632 sec.

Att 4: 2.6332 sec.

Att 5: 2.5433 sec.

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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 ave speed of each attempt is as follows.

1: 25.5/2.7187 = 9.379 cm/s

2: 25.5/2.3460 = 10.869 cm/s

3: 25.5/2.8632 = 8.906 cm/s

4: 25.5/2.6332 = 9.684 cm/s

5: 25.5/2.5433 = 10.026 cm/s

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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 made a larger version of the experiment using a 2x6 board, 1 coke can, and white tape. The tape was place at 30cm increments down the board to use as a timer refence point. I place the can on top of the board at a incline of 5cm high. I marked the time it took for the can to reach each white mark at the determined distance. I noted that the speed of the can was greater than at the bottom of the board than at the top. It's velocity increased as the rolled down the board.

Point:

1: 3.3689

2: 2.1378

3: 1.9831

4: 1.5631

5: 0.9315

That was the recored times for each mark on the board in the experiment.

Good design and your data appear to be very good also. Nice job.

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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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about 2 hours.

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

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Very good work.