Your work on pearl pendulum 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:
This may qualify as a resend. I accidentally submitted this previously without filling in the identifying information at the top of the form. I apologize for the inconvenience and I will be much more careful in the future.
Your description of the rhythm of the pendulum when tilted 'back'
When tilted back, the pearl bounce sounds occur closer together, creating a faster rythm.
Your description of the rhythm of the pendulum when tilted 'forward'
When the bracket is tilted forward, the rythm remains steady for all bounces.(seven in this case)
Your description of the process used to keep the rhythm steady and the results you observed:
I tilted the bracket forward slightly, just enough so that the pearl was hanging freely. The bounce sounds were steady to the count of seven
Your description of what happened on the tilted surface, rotating the system 45 degrees at a time:
1. Pearls closest to top of book: Pearl touching bracket 10 bounces distinctly becoming closer together as they progress 2. Pearls facing left egde of book: pearl hangs right alongside bracket. 11 bounces becoming slightly closer together, yet not as rapid a rythm as position #1. 3. Pearls facing bottom edge of book: There is a larger space between hanging pearl and bracket. 12 bounces, more of an even rythm. They still sound slightly closer together on bounces 10-12 4. Pearls face right edge of book: Pearl hangs along side of bracket. 10 bounces - appear to get slightly closer together as they progress. Similar results to position # 2.
Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm:
To obtain the most regular beat of the pendulum, I would turn the bracket so the pearls are facing the bottom edge of the book. Unlike the experiment above, I would not place the bracket in the center of the book, but I would move the whole thing closer to the top edge in order to create more space between the hanging pearl and the bracket. This results in the most regular rythm.
Your report of 8 time intervals between release and the second 'hit':
1) .297, .312, .281, .281, .312, .312
2) .360, .281, .281, .296, .312, .266
3) .328, .312, .281, .266, .297, .484
4) .281, .312, .281, .281, .328, .435
5) .281, .281, .281, .297, .266, .266
6) .312, .281, .297, .281, .312, .266
7) .343, .281, .312, .328, .328, .281
8) .281, .312, .328, .312, .281, .328
Your report of 4 trials timing alternate hits starting with the second 'hit':
1) .562, .719, .578, .609
2) .406, .500, .516, .546
3) .625, .640, .594, .578
4) .531, .484, .500, .578
The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous):
7.5 cm
Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging:
.53, .59, .55
Your description of the pendulum's motion from release to the 2d hit:
The pendulum is released, then hits the bracket in one directional movement.
Your description of the pendulum's motion from the 2d hit to 4th hit:
The pendulum hits, bounces away from the bracket, comes back towards the bracket to make contact again. This should account for a longer time period between bounces, than that of the release to the first bounce, Although, for some reason, my timing does not show the difference that it should.
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 motion between release and the second hit is 1/2 plus one whole bounce motion. The motion between the second hit and the fourth hit accounts for two whole pendulum sequences.
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 the second hit and fourth hit should be the same as that between the fourth and the sixth.
Your conjecture as to why a clear difference occurs in some intervals vs. others:
Because the actual movement of the first interval is 1/4 less than the subsequent ones.
What evidence is there that subsequent intervals increase, decrease or remain the same:
Subsequent intervals should stay the same.
What evidence is there that the time between 'hits' is independent of the amplitude of the swing?
Because in this experiment, the length of the string remained constant, but the height of the release point was not controlled.
It appears that you submitted this under a different access code; in any case the response is now posted under both codes.
Your report is good. We will be discussing this further in a few days.