phy 121
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 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 depict the same 'roll' down the ramp, at three different clock times. For each of the three readings, you just 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: I chose the roll of tape. The first one started at 59.140 and ended at 60.015. The second started at 40.031 and ended at 41.781. The third started at 28.578 and ended at 29.671. The second one was the longest at 1.75 seconds.
The three frames should all be from the same video clip, and they should all include position readings as well as clock times.
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.)..
answer/question/discussion: I don't think it would be very accutrate. Each calculation had different times. There were several variations in time, 1st is 0.875, 2nd is 1.75, and 3rd 1.093.
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: I really did not see in difference because it did not consistently speed up or slow down.
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: I really did not accuratly check the pendulum, but I did notice that it always finished after the tape.
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about 45 min
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Your observations should include both positions and clock times, and your answers should be given in terms of how you would use position and clock time data to answer these questions.
See my notes and let me know if you have questions.
You should repeat and resubmit this problem accordingly.