initial timing experiment

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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).

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:

1. A Physics Book (6th edition, used, ISBN 0-13-060620-0) was set on computer table.

2. The top end of the book was raised 0.6 cm by placing a new checkbook (containing 50 checks with carbon copies for each) underneath that end.

3. A ruler was placed on top of the book lengthwise.

4. A 10 oz. full can of Castleberry’s American Originals Hot Dog Chili Sauce with Onions was placed at the top of the book ( the raised side) and let go while at the same time the timer was started. It was caught in my hand at the bottom end of the book and the timer was stopped simultaneously.

5. Step 4 was repeated two more times and the measurements were recorded.

6. The book was turned so that the bottom end was raised 0.6 cm by the checkbook and the top end rested on the table.

7. Steps 3-5 were repeated and the measurements were recorded.

Observations:

1. The can appeared to roll down the incline at a constant rate each time.

2. The can appeared to roll smoothly in a straight path each time except in the last repeat of the first experiment in which it veered to the left as it rolled down the incline.

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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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Data:

Book length = 28.3 cm

Checkbook thickness = 0.6 cm

Height of Chili can = 10.1 cm

Diameter of Chili can = 6.3 cm

Initial Timing Experiment

event number,clock time,time interval

1 ,-6843.684 ,-6843.684

2 ,-6841.703 , 1.980469

3 ,-6827.504 , 14.19922

4 ,-6825.539 , 1.964844

5 ,-6816.758 , 8.78125

6 ,-6814.277 , 2.480469

7 ,-6758.117 , 56.16016

8 ,-6755.73 , 2.386719

9 ,-6750.941 , 4.789063

10 ,-6748.695 , 2.246094

11 ,-6745.246 , 3.449219

12 ,-6742.984 , 2.261719

Data;

Initial Timer Experiment 2

event number,clock time,time interval

1 , 16.57813 , 16.57813

2 , 17.6875 , 1.109375

3 , 27.9375 , 10.25

4 , 29.29688 , 1.359375

5 , 33.78906 , 4.492188

6 , 34.83594 , 1.046875

7 , 44.17969 , 9.34375

8 , 44.89063 , 0.7109375

9 , 52.82031 , 7.929688

10 , 53.78906 , 0.96875

11 , 59.47656 , 5.6875

12 , 60.36719 , 0.890625

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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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Experiment 1

Test Time Traveled Distance traveled Average Speed

1 1.980sec 15.7cm 7.929cm/sec

2 1.965 sec 15.7 cm 7.989cm/sec

3 2.480 sec 15.7 cm 6.331cm/sec

Experiment 2

Test Time Traveled Distance traveled Average Speed

1 2.387sec 15.7cm 6.577cm/sec

2 2.246 sec 15.7 cm 6.990cm/sec

3 2.262 sec 15.7 cm 6.9414cm/sec

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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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Setup:

1. A Physics Book (6th edition, used, ISBN 0-13-060620-0) was set on computer table.

2. The top end of the book was raised 0.6 cm by placing a new checkbook (containing 50 checks with carbon copies for each) underneath that end.

3. A ruler was placed on top of the book lengthwise.

4. A 10 oz. full can of Castleberry’s American Originals Hot Dog Chili Sauce with Onions was placed at the top of the book ( the raised side) and let go while at the same time the timer was started. It was caught in my hand at the 18cm mark on the ruler and the timer was stopped simultaneously.

5. Step 4 was repeated two more times and the measurements were recorded.

6. The 10 oz. full can of Castleberry’s American Originals Hot Dog Chili Sauce with Onions was placed at the top of the book ( the raised side) and let go. The timer was started. When the can reached the 16 cm mark It was caught in my hand at the bottom end of the book and the timer was stopped simultaneously.

7. Steps 3-5 were repeated and the measurements were recorded.

Experiment 3

Test Time Traveled Distance traveled Average Speed

1 1.109sec 5.4 cm 4.869cm/sec

2 1.359 sec 5.4 cm 3.974cm/sec

3 1.047 sec 5.4 cm 5.158cm/sec

4 .711 sec 6.2 cm 8.720cm/sec

5 .969 sec 6.2 cm 6.398cm/sec

6 .891 sec 6.2 cm 6.958cm/sec

The average speed was greater for the second set of measurements which were taken at the bottom of the incline than they were for the first three measurements which were taken at the top of the incline. This data supports the theory that the object is speeding up as it rolls down the incline.

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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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50 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. &#