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Phy 121
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.
** Initial Timing Experiment_labelMessages **
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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?
your brief discussion/description/explanation:
The book used for a ramp was Microeconomics: an intuitive approach ISBN: 978-0-538-45326-4 and was elevated on one end by a clothes pen under each corner. The height of the high end of the book was 5cm (measured from the top of the book to the ground)and the low end was 3.5cm off the ground. The length of the book is 26cm and the length the object traveled was 24cm. The object being used was a marble of 2cm diameter and rolled very smoothly down the book.
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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:
First Setup 180 degree rotation
Trial 1 1.12 sec 1.24 sec
Trial 2 1.26 sec 1.30 sec
Trial 3 1.16 sec 1.19 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.
your brief discussion/description/explanation:
Average Time For Marble to Roll down book: =(1.12+1.26+1.16+1.24+1.30+1.19)/6= 1.21sec
Average Speed = Distance Object Traveled (26cm)/ Time(1.21sec) = 21.49 cm/sec
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How fast was the object moving at the beginning of the timed interval?
It will have been traveling slower than the average speed of 21.49 cm/sec
According to your previous calculation, what was its average speed during this interval?
21.49cm/ sec
Do you think the object, when it reached the lower end of the book, was moving at a speed greater or less than the average speed you calculated?
your brief discussion/description/explanation:
Greater than average, this makes up for the lower than average speed at the beginning.
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List the following in order, from least to greatest. Indicate 'ties': The object's initial speed, its final speed, its average speed, and the change in its speed as it rolled from one end of the book to the other.
your brief discussion/description/explanation:
Change in Speed:Initial Speed: Average Speed: Final Speed
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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:
Adding a time split when the ball is half way down the book will provide the time it took to go the first half and the time it took to go the second half. Then the first half average and the second half average can be compared.
1st Half 2nd Half Total
Trial 1 .855 .343 1.198
Trial 2 .771 .289 1.060
Trial 3 .849 .326 1.175
Average .825 .319 1.144
The data cleary shows that the ball was traveling faster on the second half of the book. The average speed for the first half is 13cm( half the length of the book)/ .825 sec=15.75cm/sec and the average speed for the second half is 13cm/.319sec =40.75 cm/sec
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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?
1hr. 15min
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&#This lab submission looks very good. Let me know if you have any questions. &#