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 time intervals between strikes gets progressively smaller with each strike
** Your description of the rhythm of the pendulum when tilted 'forward' **
The time intervals between strikes gets progressively greater with each strike
** Your description of the process used to keep the rhythm steady and the results you observed: **
Shimmed the back of the bracket with a key to reach the equilibrium position. At this point the time intervals between strikes remains the same with each strike. The pearl struck the bracket 19 times discernibly.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
Parallel to the sides of the book with the pearl facing the bottom of the book - the time intervals between strikes remains the same with each strike.
45deg ccw - The time intervals between strikes gets progressively smaller with each strike
90deg ccw - The time intervals between strikes gets progressively smaller with each strike
135deg ccw - The time intervals between strikes gets progressively smaller with each strike
180deg ccw -the time intervals between strikes remains the same with each strike
225deg ccw - The time intervals between strikes gets progressively greater with each strike
270deg ccw - The time intervals between strikes gets progressively greater with each strike
315deg ccw - The time intervals between strikes gets progressively greater with each strike
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
The bracket would need to be oriented in such a way as to place the pearl in an at-rest equilibrium position relative to the bracket. This could be achieved through either very accurate measurement or trial and error rotating the bracket as needed to reach the desired position.
** Your report of 8 time intervals between release and the second 'hit': **
.344
.516
.484
.469
.516
.453
.453
.516
The are the time intervals from eight trails of timing the pendulum from release to its secong strike on the bracket
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
0.453, 0.624, 0.592, 0.562, 0.624, 0.530, 0.624, 0.624
0.500, 0.686, 0.624, 0.592, 0.562, 0.624, 0.656, 0.624
0.406, 0.592, 0.624, 0.562, 0.562, 0.500, 0.656, 0.592, 0.624
0.328, 0.592, 0.624, 0.562, 0.624, 0.592, 0.624, 0.500, 0.624
These are time intervals from every other strike of the pendulum
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
87mm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.422, .308, .308
** Your description of the pendulum's motion from release to the 2d hit: **
The motion from release to the first hit in this experiment is 1/4 of a full cycle
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
The pendulum's motion between the first and second hits is 1/2 of a full cycle. Motion from release to first hit is 1/4 of a full cycle
** 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: **
Release to second hit is 3/4 of a full cycle. Second hit to fourth hit is a full cycle.
** 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: **
No difference in terms of cycle although the length of swing decreases with each cycle. Time intervals of each cycle is theoretically identical. Here we have atmospheric and friction interferences to contend with.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
Because the first reported time interval is only 3/4 of a full cycle while the subsequent intervals are of a full cycle
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
Remain the same if the bracket is acurately placed with the pearl in equilibrium at rest
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
There are many other factors that affect a pendulum's swing in the real world - friction, gravity fluctuations, atmosphereic interfenence. An ideal pendulum's swing would be directly related to its length
** **
50min
** **
Excellent report. Most students don't see the 3/4 and full cycles between release and 2d hit, and then between subsequent hits.