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' **
When the pendulum first strikes the bracked the sound is strong causing a quick rhythm, but then the sound gets softer with the tinking sound getting closer together.
** Your description of the rhythm of the pendulum when tilted 'forward' **
The sounds get further apart with a slower rhythm. When the pendulum is first release, it strickes the bracket with a strong sound, but then the more it goes back and forth the sound gets quiter and the sound sounds like it gets further and further away.
** Your description of the process used to keep the rhythm steady and the results you observed: **
In order to keep the steady rhythm I placed under the bracked my ruler and then I tilted the bracket forward a bit until there were 10 consecutive hits up against the bracket that were in equal rhythm.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
Place bracket pendulum in middle of book with base of bracket parallel to one side of the book , the sounds eventually get further apart.
Place bracket pendulum roated 45 degrees to the left where it is in the middle of the book where base of the bracket is parallel to one width of the book, the sounds get closer together but at a steadier rate.
Place bracket pendulum rotated 45 degrees left from previous spot where pendulum bracket is in middle with base fo the bracket is slanted downard and pendulum part is facing where the dominoes are, the sound gets closer together.
Place bracket pendulum rotated 45 degrees from previous spot where it is in the middle of the book where base of bracket is parallel to the width fo the book, the sounds get closer together but at a steadier rate.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
Place the bracket pendulum in the middle of the book where base of bracket is parallel to one width side and parallel to the other width side with the dominoes are placed under the top left and right corners of the book
** Your report of 8 time intervals between release and the second 'hit': **
.359
.437
.313
.313
.328
.250
.344
.203
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.313, .609, .578, .672
.422, .546, .625
.344, .594, .563
.297, .547, .594, .593
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
From the bottom of the bolt to the center of the pearl, the length of the pendulum is 9cm.
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.23 , .016, -.001
** Your description of the pendulum's motion from release to the 2d hit: **
very quick, sound was loud and bounced back quick
&#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.
&#
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
quick but slower than inital hit, sound was still loud
** 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 is further out, the second hit was louder and while the fourth hit was softer but the motion on the fourth is quicker since it was getting closer to the bracket.
** 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 2nd and 4th hit is that the 4th hits motion is quicker, but the difference in the fourth hit and the sixth hits motion is that the sixth's hit has much quicker motion since it was very close to the bracket.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
the first time inervals should be the longest
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
time intervals would decrease
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
each trial has different hits therefore casuing the length to be dependent on its length and causing it to be independent to how far it actually swings since there is not set numbers of hits.
** **
1 1/2 hours
** **
You appear to have excellent data. Include your data with the response requested above, and my subsequent response will allow you to easily determine just how good it is.