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 gets faster. The sound of the ball hitting the bracket definitly increases in frequency.
** Your description of the rhythm of the pendulum when tilted 'forward' **
rhythm gets slower. The rhythm of the ball against the bracket is much less frequent than before.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I placed the bracket on my desk. This should be a level surface however i noticed that the ball was not just touching the bracket. I adjusted the bracket with a shim so that it was as close to level as possible. The rhythm was much more steady than before. I would say hitting about every second. The pendulum hit the bracket six times.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
I placed four regular dominos under my textbook so that the textbook was obviously raised slightly off my desk. I then placed my pendulum on the inside page of the textbook. I placed it so that base of the pendulum was parallel to the bottom of the textbook and observed the frequency of the pendulum. I then rotated the pendulmn 45 degrees and observed again. I rotated in the same fashion until the pendulum was back in its original position.
rotation 1: sounds get closer to together and less regular.
rotation 2: (90 deg) sounds become regular again like at starting position.
rotation 2: 135 deg-sounds become more frequent, less regular
rotation 3: 180 deg- sounds regular again.
rotation 4: 225 deg-sounds become more frequent, less regular
rotation 5: 270 deg- sounds regular again.
rotation 6: 315 deg-sounds become more frequent, less regular
rotation 7: 360 deg- sounds regular again.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
I would orient the bracket at 0, 90, 180, 270, and 360 degrees to the original positon.
** Your report of 8 time intervals between release and the second 'hit': **
.703
.741
.712
.737
.701
.703
.717
.698
I would similtaneously release the pendulum and start the timer. I would then click the timer again when the pendulum hit the bracket the second time. I did this eight times. Each time is the interval of time it took for the pendulum to be released, hit, swing back out, and hit again.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.709, .921875, .967, .968
.875, .96875, .953125, .890625
.805, .988, .940, .935
.876, .955, .899, .9375
These results show the time intervals between time realeased and ever two hits. So, the second, fourth, and sixth hits.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
9.05 cm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.75, .95, 93
** Your description of the pendulum's motion from release to the 2d hit: **
The pendulum will travel from one extreme position into equilibrium position at the bracket.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
From equilibrium, to extreme postion and back to equilibrium.
This starts at equilibrium instead of the extreme position and hits equilibrium twice instead of once.
** 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 extreme positions that the pendulumn returns to are not as extreme in the second and fourth hit when compared to the realease and second hit. (does not travel as far)
** 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 motion between second and fourth hit is greater than that of the fourth and sixth hit. The extreme is further out.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
Has more potential energy and will travel fastest.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
increase.
If the times increase then it means you didn't quite get the pendulum set so that the rhythm is steady. There isn't much increase so you came close.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
Well the pendulum's length of swing depends on the length but also the position at which the pendulumn is released and how extreme it is. The evidence lies in the time intervals of the second fourth and sixth hits. The time intervals increase.
The time between 4th and 6th hits, or between 6th and 8th, does not appear to increase. It is possible that you systematically anticipated the 4th 'hit' and/or delayed your click of the 2'd 'hit'.
In anyc ase your intervals didn't vary drastically.
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1 hour
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&#Good responses. See my notes and let me know if you have questions. &#