phy201
Your 'pearl pendulum' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** Your general comment, if any: **
** Your description of the rhythm of the pendulum when tilted 'back' **
The rhythm get faster.
** Your description of the rhythm of the pendulum when tilted 'forward' **
The rhythm slows down.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I moved my bracket around on the table until the pearl was just barely touching the bracket. The rhythm was steady for about 6 beats.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
While the pearl of the bracket was facing the top of the book the rhythm got faster. While facing right side the rhythm got slower. While facing the bottom of the book the rhythm got slower. While facing the spine of the book the rhythm was very steady.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
I would face the pearl toward the spine of the book.
** Your report of 8 time intervals between release and the second 'hit': **
.441
.398
.461
.441
.453
.430
.527
.578
This tells me that I had an avg of .466. This data was skewed just a bit by the last measurement. They were obtained by measuring the time between the release of the pearl and it's second strike on the bracket.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.570, .480, .469, .652
.640, .441, .578
.672, .508, .504
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
85mm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.62, .476, .517
** Your description of the pendulum's motion from release to the 2d hit: **
The motion of the pendulum between release and first hit is the pearl falls from it's extreme point on a circular path until it makes contact.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
After the first hit, the pearl bounces off of the bracket rising to less than half of the extreme point and then follows the same path and makes contact a second time.
** Your description of the difference in the pendulum's motion from release to the 2d 'hit', compared to the motion from the 2d 'hit' to the 4th hit: **
the pendulum is not moving as far between the second hit and the fourth hit.
** Your description of the difference in the pendulum's motion from the 2d to the 4th 'hit' compared to the motion from the 4th to 6th hit: **
the pendulum is not moving as far between the fourth hit and the sixth hit.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
More speed.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
decrease at first then begin to increase until there is rapid contact and the pendulum stops.
If the pendulum is set up, as instructed, to achieve a constant rhythm that there should not be rapid contact near the end, nor should the intervals vary dramatically.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
This supports it because we have a barrier stopping the pendulum so the only thing we have to base the length of the pendulum's swing on is the length of the pendulum.
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1 hr
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&#Good work. See my notes and let me know if you have questions. &#