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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Take reasonable care to get good data in this experiment. Try to do the timing as accurately as possible. Measurements of length, height, etc. should be reasonably accurate (e.g., with a meter stick or ruler you can measure to withing +- 1 millimeter, but it's not necessary to try to determine fractions of a millimeter).
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 three 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 can of vegetables (full or empty; should be specified) or a jar (again full or empty); anything round and smooth that will upon release roll fairly slowly down the incline), 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: Never trust Web forms. 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. (However you should understand that if a Web form gives you a confirmation, then it has almost certainly worked correctly and sent the data to the appropriate file. It's still a good idea to keep a copy of the confirmation.)
your brief discussion/description/explanation:
The book I used for the object to roll on was the physics textbook that is required for this class. I propped it up with another textbook. It is called Tourism, it is the 11th edition and it is by Charles R. Goeldmer. The object I used to roll on the book was a cylindrical cardboard colored pencil case. The object rolled down smoothly each time. The object rolled down 22 cm. It took about 0.53125 seconds to roll down.
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In the space indicated 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 identify any patterns or trends.
your brief discussion/description/explanation:
The length of the book where the object rolled down was measured. It came out to be 22 cm. I believe it was accurately measured because I used a ruler. The only issue would be that there would be human error because it the measurement was viewed with the human eye.
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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.
your brief discussion/description/explanation:
On average it rolled down 0.53125 seconds. I am not extremely confident with how accurate this value is though because it was difficult having to push start as I let go of the cylinder and stop it right when the cylinder fell. There are many possibilities for human error.
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Devise and conduct 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.
your brief discussion/description/explanation:
I measured the time from the start to middle, middle to end to see which segment had a shorter value. The start to middle was 0.699 seconds whereas the middle to end time was 0.563 seconds. This shows that it was 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:
Approximately how long did it take you to complete this experiment?
25 minutes
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You may also include optional comments and/or questions.
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&#Very good responses. Let me know if you have questions. &#