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.
** **
Top of Form 1
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):
#$&*The object that I used was the pendulum
At 40.25 the pendulum had just started to swing and was near the beginning of the ramp. At 41.34 the pendulum had swung almost to the opposite end of the ramp. At 42.54 the pendulum was approximately back to the position from which it started..Idid not give actual cm here because I could not see it on the screen. The large view would not open for me.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
In the following you don't have to actually do calculations with your actual data. Simply explain how you would use data of this nature if you had a series of several position vs. clock time observations:
If you did use observations of positions and clock times from this video, how accurately do you think you could determine the positions, and how accurately do you think you would know the clock times? Give a reasonable numerical answer to this question (e.g., positions within 1 meter, within 2 centimeters, within 3 inches, etc; clock times within 3 seconds, or within .002 seconds, or within .4 seconds, etc.). You should include an explanations of the basis for your estimate: Why did you make the estimate you did?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I think you could determine the position within 1-2 centimeters and clock times within .01 of a second. I used these estimations because when we stop the video you have a still frame of the time and positions of the object. Had I been able to see the ruler more clearly I would have been able to get an approximate measurement.
#$&*
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 could look at the position of the tape frame by frame and determine at different points the rate at which the tape is rolling. So, if the position of the tape is at a certain distance and is increasing distance at a decreasing amount of time then the tape is getting faster.
#$&*
How can you use observations of position and clock time to determine whether the swinging pendulum is speeding up or slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
You could look at the position of the pendulum in comparison to the time, and if the position is increasing in a less amount of time then the pendulum’s speed is increasing. If the position of the pendulum is increasing at an increasing amount of time then the pendulum is slowing down.
#$&*
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):
You could observe the time it take the pendulum to get to each position and the frequency at which it returns to each position, once the frequency of its return at a particular point gets slower that will be the point the pendulum started to slow.
#$&*
Challenge (University Physics students should attempt answer Challenge questions; Principles of Physics and General College Physics may do so but it is optional for these students): How could you use your observations to determine whether the rate at which the tape is speeding up is constant, increasing or decreasing?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
Since d=r*t distance could from observing the tape at 3cm at 42 second and then at 5 cm at 43 seconds 3-5=2 ,42-43=1 2=r*1 r=2 secondper centimeter……then if it is at 6cm at 43.5 and at 7 cm at 43.2 then 1cm=r*0.3 then it is going a rate of 3.33 since the rate is speeding up the tape is getting faster. So get the rate at different points to see if it is getting faster or slower.
#$&*
Check to see that you have followed the instructions:
The instructions told you to pause the video multiple times. It appears that some students are not following this instruction.
If you haven't used the 'pause' and 'play' buttons on your media player, you should go back and do so.
The questions are phrased to ask not only what you see when you play the video, but what you see when you pause the video as instructed, and what you think you could determine if you were to actually take data from the video. You aren't asked to actually take the data, but you need to answer how you would use it if you did.
It's OK if you have given more general descriptions, which are certainly relevant. But answers to the questions should include an explanation of how you could use the series of position and clock time observations that are may be observed with this video.
The questions also ask how much uncertainty there would be in the positions and clock times observable with this specific video. Different people will have different answers, and some reasonable answers might vary from one clip to the next, or from one part of a clip to another. However the answers should include a reasonable quantitative estimate (i.e., numbers to represent the uncertainty; e.g., .004 seconds of uncertainty in clock times, 2 inches in position measurements. Use your own estimates; neither of these example values is necessarily reasonable for this situation). You should also explain the basis for your estimate: why did you make the estimate you did?
You should have estimated the number of seconds or fraction of a second to within which you think the time displayed on the computer screen might be accurate (e.g., is it accurate to within 10 seconds of the actual clock time, or to within 1 second, within .1 second, maybe even within .01 or .001 second). You might not yet know enough about the TIMER to give an accurate answer, but give the best answer you can.
You should also indicate a reasonable estimate of the number of inches or fraction of an inch to within which you could, if asked, determine the position of each object.
Copy and paste your work into the box below and submit as indicated:
Your instructor is trying to gauge the typical time spent by students on these questions. Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades:
Approximately how much time did you spend on this question?
About 1 hour
You may add optional comments and/or questions in the box below.
Bottom of Form 1
Author information goes here.
Copyright © 1999 [OrganizationName]. All rights reserved.
Revised: 23 Jan 2010 13:47:47 -0500
** **
1 hour
** **
&#Very good work. Let me know if you have questions. &#
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.
** **
Top of Form 1
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):
#$&*The object that I used was the pendulum
At 40.25 the pendulum had just started to swing and was near the beginning of the ramp. At 41.34 the pendulum had swung almost to the opposite end of the ramp. At 42.54 the pendulum was approximately back to the position from which it started..Idid not give actual cm here because I could not see it on the screen. The large view would not open for me.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
In the following you don't have to actually do calculations with your actual data. Simply explain how you would use data of this nature if you had a series of several position vs. clock time observations:
If you did use observations of positions and clock times from this video, how accurately do you think you could determine the positions, and how accurately do you think you would know the clock times? Give a reasonable numerical answer to this question (e.g., positions within 1 meter, within 2 centimeters, within 3 inches, etc; clock times within 3 seconds, or within .002 seconds, or within .4 seconds, etc.). You should include an explanations of the basis for your estimate: Why did you make the estimate you did?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I think you could determine the position within 1-2 centimeters and clock times within .01 of a second. I used these estimations because when we stop the video you have a still frame of the time and positions of the object. Had I been able to see the ruler more clearly I would have been able to get an approximate measurement.
#$&*
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 could look at the position of the tape frame by frame and determine at different points the rate at which the tape is rolling. So, if the position of the tape is at a certain distance and is increasing distance at a decreasing amount of time then the tape is getting faster.
#$&*
How can you use observations of position and clock time to determine whether the swinging pendulum is speeding up or slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
You could look at the position of the pendulum in comparison to the time, and if the position is increasing in a less amount of time then the pendulum’s speed is increasing. If the position of the pendulum is increasing at an increasing amount of time then the pendulum is slowing down.
#$&*
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):
You could observe the time it take the pendulum to get to each position and the frequency at which it returns to each position, once the frequency of its return at a particular point gets slower that will be the point the pendulum started to slow.
#$&*
Challenge (University Physics students should attempt answer Challenge questions; Principles of Physics and General College Physics may do so but it is optional for these students): How could you use your observations to determine whether the rate at which the tape is speeding up is constant, increasing or decreasing?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
Since d=r*t distance could from observing the tape at 3cm at 42 second and then at 5 cm at 43 seconds 3-5=2 ,42-43=1 2=r*1 r=2 secondper centimeter……then if it is at 6cm at 43.5 and at 7 cm at 43.2 then 1cm=r*0.3 then it is going a rate of 3.33 since the rate is speeding up the tape is getting faster. So get the rate at different points to see if it is getting faster or slower.
#$&*
Check to see that you have followed the instructions:
The instructions told you to pause the video multiple times. It appears that some students are not following this instruction.
If you haven't used the 'pause' and 'play' buttons on your media player, you should go back and do so.
The questions are phrased to ask not only what you see when you play the video, but what you see when you pause the video as instructed, and what you think you could determine if you were to actually take data from the video. You aren't asked to actually take the data, but you need to answer how you would use it if you did.
It's OK if you have given more general descriptions, which are certainly relevant. But answers to the questions should include an explanation of how you could use the series of position and clock time observations that are may be observed with this video.
The questions also ask how much uncertainty there would be in the positions and clock times observable with this specific video. Different people will have different answers, and some reasonable answers might vary from one clip to the next, or from one part of a clip to another. However the answers should include a reasonable quantitative estimate (i.e., numbers to represent the uncertainty; e.g., .004 seconds of uncertainty in clock times, 2 inches in position measurements. Use your own estimates; neither of these example values is necessarily reasonable for this situation). You should also explain the basis for your estimate: why did you make the estimate you did?
You should have estimated the number of seconds or fraction of a second to within which you think the time displayed on the computer screen might be accurate (e.g., is it accurate to within 10 seconds of the actual clock time, or to within 1 second, within .1 second, maybe even within .01 or .001 second). You might not yet know enough about the TIMER to give an accurate answer, but give the best answer you can.
You should also indicate a reasonable estimate of the number of inches or fraction of an inch to within which you could, if asked, determine the position of each object.
Copy and paste your work into the box below and submit as indicated:
Your instructor is trying to gauge the typical time spent by students on these questions. Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades:
Approximately how much time did you spend on this question?
About 1 hour
You may add optional comments and/or questions in the box below.
Bottom of Form 1
Author information goes here.
Copyright © 1999 [OrganizationName]. All rights reserved.
Revised: 23 Jan 2010 13:47:47 -0500
** **
1 hour
** **
&#Very good work. Let me know if you have questions. &#