cq_1_001

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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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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):

Video three

Pendulum

29.343 10 inches

29.015 2 inches

29.562 16 inches

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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):

I think time would be within 0.005 of the second. The computer was not that blurry through most of the video which made it easier to read. The distance would be within 1 inch in either direction. This number will be less accurate than the time due to the fact the measure was very blurry.

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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):

You can measure at a set time interval i.e. 0.5 seconds or 0.05 seconds, and take measurement at each time. Then you can subtract the distances from one another to see if the distance interval is staying constant 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):

You can use the observations in the same way that you did using the tape measure.

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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):

Take measurement of the pendulum at an even time variable of 0.05 seconds. Then subtract the distance between the two points. Do this every 0.05 seconds until you see the intervalbetween distances start to decrease. If the interval decreases then the pendulum is not making as much distance therefore, it has slowed down.

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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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&#This looks very good. Let me know if you have any questions. &#