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' **
With the bracket tilted back the thythm of the ball sticking The bracket appears to increase ntil the ball stops against the backet.
** Your description of the rhythm of the pendulum when tilted 'forward' **
With the bracket tilted forward the thythm of the ball striking the bracket gets slower ntil the ball still swings on the pendulum but does not strike the bracket.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I placed the bracket on a table with a small piece of cardboard under the front of the bracket to level it. I adjusted the string until the ball was close to the bottom of the bracket. The sound of the ball striking the bracket becam continuous. The ball striked the pendulum 14 times before stopping.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
Placce 2 dominoes under front of a book on the left and right corners. Place the pendulum in the center of the book. The rhythum of the ball striking the bracket decreases rotating 45 degrees counter clockwise. As you continuously rotate the pendulum at 45 degree intervals until you reach 180 degrees from starting point the sound decreases. Once you start rotating 45 degrees back towards your starting position still going counter clockwise the sound increases until you reach your starting point.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
place pendulum on the table and level it so the ball is just resting against the bracket.
** Your report of 8 time intervals between release and the second 'hit': **
.500
.469
.422
.422
.453
.438
.422
.453
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.641
.531
.500
.531
.609
.594
.484
.578
.609
.531
.515
.531
.641
.594
.514
.578
The results show that the ball striking the bracket is fairly constant and would be consistent if not for human error.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
90mm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.500,.515,.531,.594
** Your description of the pendulum's motion from release to the 2d hit: **
The pendulum starts hit at extreme point and strikes at the equilibrium point
Between release and the second 'hit' it returns to an extreme point, which should be noted. It's not the same extreme point as before--a little closer due to energy loss--but it's still a relative extreme.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
After first hit the pendulum travels back but does not reach the extreme point but does strike at hits equilibrium point.
** 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: **
Same as above but travels back at even a less amount than before.
&#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 difference in the pendulum's motion from the 2d to the 4th 'hit' compared to the motion from the 4th to 6th hit: **
same as previous
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
because it is traveling faster rate of speed.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
to decrease with each swing due to the length of the swing after each strike because of loss of energy and momentum.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
because of the transfer and loss of energy with each swing and strike
** **
2 hours
** **
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Your responses have been reviewed and everything looks good.
Please let me know if you have any questions related to this orientation assignment.