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 sounds made seem to be pretty constant, speeding up only very slightly
** Your description of the rhythm of the pendulum when tilted 'forward' **
these sounds are sort of constant, but tend to slow down a little
** Your description of the process used to keep the rhythm steady and the results you observed: **
it was quite constant and hit the bracket 14 times
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
i started with the bracket facing uphill and turned it clockwise with each rotation
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
i would orient the bracket facing slightly downhill to obtain the most regular beat
** Your report of 8 time intervals between release and the second 'hit': **
.281
.312
.343
.218
.312
.265
.343
.359
these are the timed intervals between the time i released the intervals until the second bounce
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.484, .5, .578, .578
.546, .531, .546, .578
.562, .593, 468, .593
.546, .546, .609, .609
these are the intervals between every second click, i did four trials that are represented by the numbers above
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
my pendulum is about 6.9 cm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.29, .54, .59
** Your description of the pendulum's motion from release to the 2d hit: **
the release and first hit was very fast because it only had half the distance to go
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
it had to go from bracket to equilibrium and back to bracet so it was about twice as long - i think i did this right!!
** 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 second hit and release differed a little from the fourth hit but they were closer
** 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 fourth and the sixth were much further apart than the initial ones
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
because it only had to go from equilibrium to bracket on the first swing
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
increase, as the equilibrium gets closer
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
the equilibrium seems to reach a crest and then moves closer and closer to the bracket with each bounce, as momentum subsides
** **
45 minutes
** **
You need a more detailed description of the motion of the pendulum.
&#A full cycle of a free pendulum is from extreme point to equilibrium to opposite extreme point then back to equilibrium and finally back to (almost) the original extreme point. The pearl pendulum is released from an 'extreme point' and strikes the bracket at its equilibrium point, so it doesn't get to the opposite extreme point.Thus the period of the pendulum can be divided into four parts. From the steadiness of the rhythm we have good evidence that the motion between 'hits' takes the same time independent of the amplitude of the motion (the rhythm remains constant while the amplitude of the motion decreases). Theoretically each of the four parts of the cycle, as described above, takes the same time. Assuming this to be true, we can speak of the quarter-cycle from an extreme point to equilibrium or from equilibrium to an extreme point.
Through how many quarter-cycles does the pendulum move between release and the second 'hit'?
Through how many quarter-cycles does it move between the second and the fourth 'hit'?
What therefore should be the ratio of the time interval from 2d to 4th 'hit', to the interval from release to the 2d 'hit'?
How does this ratio compare with the results you just reported?
Does this constitute evidence for or against the theoretical hypothesis that the quarter-cycles all require the same time?Suggested response title: description of motion of pearl pendulum &#
&#Please respond with a copy of this question, a copy of any other part of this document you wish to include, and your response to the question. Indicate your response using the symbols *&##. As your title use the 'response title' suggested above (just copy and paste that title into the Title box of the Submit Work form); if no suggested title was given use your own title.
&#