Phy 201
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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I tried to do the last experiment to see if the object is really speeding up and how to calculte it, but I am not really sure. I wrote in my experiment what I thought but I am still confused on how you can figure this.
Thanks
Natalie
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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.
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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.
First time: 2.52 seconds
Seond Time: 2.39 seconds
Third Time: 2.51 second
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Determine how far the object actually travels as it rolls from one end to the other.
From one end of the book to the other end of the book is 22.4 centimeters
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Determine how much higher one end of the book was than the other, and how far it is from one end to the other.
The highest end f the book is 3.5 centimeters. The lowest end of the book was 3 cm.
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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.
Total length of travel 22.4 centimeters
Timer:
First: 2.12s
Second: 1.79s
Third: 1.84s
Highest End: 3.5 cm
Lowest End: 3.0 cm
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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?
The book I used was our text book, Physics sixth edition by Giancoli. The object I used was a Duracell size D battery. I used 1 glass drink coaster to prop up the book, the coaster was .4 of a centimeter
that totaled a level of 3.5 centimeters in height for the book once propt up. The object rolled smoothly in a straight line, which surprises me since the floor which my desk is setting on tends to lean
toward me, but this did not seem to effect the battery as it rolled straight down the ramp. The battery sped up as it went down the ramp, but at a rate that is not so obvious, you really have to observe
closely to see this. Once I rotated the book 180 degrees the time it took the battery to roll down the ramp had decreased even though the length and the height were the same. This may be do to the desk
itself leaning in that direction, which may not disturb my measurements but it would make the object roll faster.
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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:
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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.
I included the data at the top of this document. Directly after each question.
your brief discussion/description/explanation:
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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.
on average the object was moving 2.47 seconds as it rolled down the incline on the first trial, on the second trial it averaged 1.92 seconds. To estimate the objects averae speed I would use the formula
D=r*t
It rolled a distance of 22.4 centimeters= average time (2.47)seconds * rate 22.4cm/2.47s= 9.07 cm/s was the average speed for the first trial
22.4cm/1.92s= 11.67cm/s for the second trial.
your brief discussion/description/explanation:
As I stated before I think that the average speeds for the first and second trials are different to the the level of the desk that the incline was sitting on. Even though all measurements stayed the same
the object sped up.
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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.
Using D=r*t
Explain how you designed and conducted your experiment, give your data and explain how your data support your conclusions.
your brief discussion/description/explanation:
Ok, I tried to time from one point to another, as in from, the start to about half way down the incline, and then from the half wasy point to the end of the incline
but it seemed to slow. I know this is not accurate and I am sure stopping and starting the object throws the time off.
I am really not sure how to do this. But it would seem if you could measure from one point to another and then from that point to another, you could see how it speeds up, I just dont know how to do that or
calculate it.
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It took me about one hour to conduct this experiment
&#Good work. Let me know if you have questions. &#