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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You don't have to actually do so, but it should be clear that if you wished to do so, you could take a number of observations of positions and clock times. The point here is to think about how you would use that information if you did go to the trouble of collecting it.
• If you did take observations of positions and clock times, how accurately do you think you could determine the positions, and how accurately do you think you would know the clock times?
answer/question/discussion: the position could be determine very close to the number but there will always be a small factor of looking through a lens that can make the number change. The clock times would be the most accurate of anything because it is in a fixed place and by stopping the video you could play on slow motion to get the closes answer.
• How can you use observations to determine whether the tape rolling along an incline is speeding up or slowing down?
answer/question/discussion: the speed of the tape will increase as it continues down the incline due to the gravitational forces pulling on the role of tape. The role on tape will slow down when it reaches the end of the tape measure.
• How can you use your observations to determine whether the swinging pendulum is speeding up or slowing down?
answer/question/discussion: the pendulum is slowing at a very slow rate because the pull of gravity on it. If this was in a vacuum chamber the pendulum would continue at the same rate.
• 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: the pendulum starts to slow down when it starts to reach equilibrium and starts to speed up after it makes the turn and starts the other direction. The maximum speed would be when the pendulum is at the middle of the cycle. The slowest part of the pendulum will have a longering time of a few milla seconds.
• 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: measure the distance in different sections and see the difference of speeds and add them together to get the final speed to prove that the roll of tape is speeding up.
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30 minutes
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i hope you can understand what i tried to explain. i think that i have a understanding of what is going on with the tape and the pendulum.
Good answer and good concepts, but your amswers were generally in conceptual rather than operational terms. You describe what you think is going on in the system, and most (but not all) of your descriptions and conceptualizations are valid. However you don't say exactly what you would measure or how you would use it to answer the questions.
Consider the statements and questions below, isolating one question from the set:
You don't have to actually do so, but it should be clear that if you wished to do so, you could take a number of observations of positions and clock times. The point here is to think about how you would use that information if you did go to the trouble of collecting it.
• How can you use your observations to determine whether the swinging pendulum is speeding up or slowing down?
answer/question/discussion: the pendulum is slowing at a very slow rate because the pull of gravity on it. If this was in a vacuum chamber the pendulum would continue at the same rate.
Your answer includes some good thinking about the physics behind the system and speculation about what would happen in a vacuum. These are very good things to think about. You are in fact forming some good hypotheses which can be tested by experiment, and it is very good that you can do so at this early point in the course. However your answer does not address how you would use the data you can get from this tape, specifically a series observations of positions and clock times, to determine whether the swinging pendulum is speeding up or slowing down.
I'm going to ask you to submit a copy of this document, and add some additional comments (and/or questions) addressing the question of how you would use specific position and clock time observations to answer the various questions. Just copy this entire document into the same form, and mark your insertions using &&&& before and after each.