#$&*
Phy 201
Your 'cq_1_00.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** CQ_1_00.1_labelMessages **
The problem:
You don't have to actually do so, but it should be clear that if you wished to
do so, you could take several observations of positions and clock times. The
main point here is to think about how you would use that information if you did
go to the trouble of collecting it. However, most students do not answer these
questions in terms of position and clock time information. Some students do not
pause the video as instructed. To be sure you are thinking in terms of
positions and clock times, please take a minute to do the following, which
should not take you more than a couple of minutes:
Pick one of the videos, and write down the position and clock time of one of the
objects, as best you can determine them, in each of three different frames. The
three frames should all depict the same 'roll' down the ramp, i.e. the same
video clip, at three different clock times. They should not include information
from two or more different video clips.
For each of the three readings, simply write down the clock time as it appears
on the computer screen, and the position of the object along the meter stick.
You can choose either object (i.e., either the pendulum or the roll of tape),
but use the same object for all three measurements. Do not go to a lot of
trouble to estimate the position with great accuracy. Just make the best
estimates you can in a couple of minutes.
Which object did you choose and what were the three positions and the three
clock times?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I chose the pendulum.
Clock time Position
59.463 3 in
59.906 17 in
60.234 22 in
#$&*
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):
From viewing on this video, the position measurements are probably accurate to
the nearset 2 inches because the width of the pendulum overshadows the
measurements on the ruler. The times is accurate to the nearest 0.001 of a
second, because in each of my 3 time intervals, they were specific to a
thousandsth of a second and did not round up to the nearest set interval.
#$&*
@&
This is a plausible expectation since the time is displayed to the nearest .001 second. However a displayed time will persist on the screen for many milliseconds, so the times you see do not have that much precision.
*@
How can you use observations of position and clock time to determine whether the
tape rolling along an incline is speeding up or slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
You can compare how far the object has traveled over equal time intervals.
#$&*
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):
In the same way as the tape, I would measure the position at equally spaced time
intervals to determine how far the pendulum moves over an amount of time.
#$&*
Challenge (University Physics students should attempt answer Challenge
questions; Principles of Physics and General College Physics may do so but it is
optional for these students): It is obvious that a pendulum swinging back and
forth speeds up at times, and slows down at times. How could you determine, by
measuring positions and clock times, at what location a swinging pendulum starts
slowing down?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
#$&*
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):
#$&*
*#&!
&#This lab submittion looks good. See my notes. Let me know if you have any questions.
Revision isn't requested, but if you do choose to submit revisions, clarifications or questions, please insert them into a copy of this document, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes. &#