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PHY 201
Your 'cq_1_00.1' 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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Samantha Rogers
PHY 201
Seed Question One
The problem:
You don't have to actually do so, but it should be clear that if you wished to do so, you could take several observations of positions and clock times. The main point here is to think about how you would use that information if you did go to the trouble of collecting it. However, most students do not answer these questions in terms of position and clock time information. Some students do not pause the video as instructed. To be sure you are thinking in terms of positions and clock times, please take a minute to do the following, which should not take you more than a couple of minutes:
• Pick one of the videos, and write down the position and clock time of one of the objects, as best you can determine them, in each of three different frames. The three frames should all depict the same 'roll' down the ramp, i.e. the same video clip, at three different clock times. They should not include information from two or more different video clips.
• For each of the three readings, simply write down the clock time as it appears on the computer screen, and the position of the object along the meter stick. You can choose either object (i.e., either the pendulum or the roll of tape), but use the same object for all three measurements. Do not go to a lot of trouble to estimate the position with great accuracy. Just make the best estimates you can in a couple of minutes.
Which object did you choose and what were the three positions and the three clock times?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I chose the tape.
First clock time: 40.578, 8.5
Second clock time: 40.796, 11.5
Third clock time: 41.125, 20
Discussion: it is clear to me that the tape does indeed speed up, according to my listed positions and times recorded.
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In the following you don't have to actually do calculations with your actual data. Simply explain how you would use data of this nature if you had a series of several position vs. clock time observations:
• If you did use observations of positions and clock times from this video, how accurately do you think you could determine the positions, and how accurately do you think you would know the clock times? Give a reasonable numerical answer to this question (e.g., positions within 1 meter, within 2 centimeters, within 3 inches, etc; clock times within 3 seconds, or within .002 seconds, or within .4 seconds, etc.). You should include an explanations of the basis for your estimate: Why did you make the estimate you did?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
On the graph using the three data points collected, after connecting the data points, the graph most likely wouldn't be very accurate.
I do not think that you could accurately determine the positions and clock times. I think the smallest accurate number you could measure would be 1 inch. Clearly with the clock given you can be accurate to 0.001 seconds. I made the basis of my estimate for 1 inch because those are the only dashes/lines on the measuring tape that are legible for me.
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• How can you use observations of position and clock time to determine whether the tape rolling along an incline is speeding up or slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
To determine whether the tape rolling along an incline is speeding up or slowing down I could attempt to record the time as the tape passes at every inch marked. With that data I would clearly be able to notice if the time increments recorded are increasing or decreasing.
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• How can you use observations of position and clock time to determine whether the swinging pendulum is speeding up or slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
To determine whether the pendulum speeding up or slowing down I could attempt to record the time as the pendulum passes at every inch marked. Then I would also record the times the pendulum passes at every inch as it goes back (completing the cycle). With that data I would clearly be able to notice if the time increments recorded are increasing or decreasing.
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• Challenge (University Physics students should attempt answer Challenge questions; Principles of Physics and General College Physics may do so but it is optional for these students): It is obvious that a pendulum swinging back and forth speeds up at times, and slows down at times. How could you determine, by measuring positions and clock times, at what location a swinging pendulum starts slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
To determine at what location a swinging pendulum starts slowing down is the measure the distance that it is traveling in one complete cycle and to time everyone. Then make a graph on the time it took to cover the distance vs. the distanced covered.
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• Challenge (University Physics students should attempt answer Challenge questions; Principles of Physics and General College Physics may do so but it is optional for these students): How could you use your observations to determine whether the rate at which the tape is speeding up is constant, increasing or decreasing?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
You could determine whether the rate at which the tape is speeding up by collecting the time at every inch. By doing this you know whether or not the time it took to cover an inch of distance is equal to, more then, or less then the time taken for the inch prior.
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&#Your work looks very good. Let me know if you have any questions. &#