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PHY201
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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The videos
Is the tape speeding up or slowing down?
The tape seems to be speeding up going down the incline.
Is the pendulum speeding up or slowing down?
The pendulum seems to be building momentum going through a half a cycle, but starts to slow down when making one complete resolution.
Which speeds up faster, the tape or the pendulum?
The tape speeds up faster than the pendulum.
What is going to limit your ability to precisely measure the positions of these objects?
The clarity with which I can read the measurements on the video also when the experiment was conducted because the object is always in motion. it will prove very difficult to read.
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?
The pendulum
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
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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):
For the length of the pendulum i could only state with accuracy of between 1 to inches. This was due to the visibility of the ruler and the thickness of the pendulum. The pendulum appears to be about 1 to inches wide, therefore accurately measuring the length on the meter was blocked. However i gathered three readings, by pausing the video. However due the accuracy of the clock on the computer, the time could be measured to 1000th of a sec.
at rest, 1-2inches, 58.156
6-4 inches, 58.484
16-18 inches 58.956
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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):
We can record the tape a rest, then at other intervals on the incline and take a difference in those times. This will tell us if it taking less time to move from points a to b... then we will be able to tell if the tape is rolling faster or not.
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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):
We can record the different times it takes to complete a full cycle or a half a cycle, then see if that time gets longer or shorter. Then we can deduce whether are not the pendulum is slowing down or speeding up
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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):
We could record the a number of different start an stop time on the pendulum and there positions. The compare the times between theses different positions of the pendulum. The shorter times would be able to tell us when the pendulum is going faster.
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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):
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&#Good responses. Let me know if you have questions. &#