phy 201
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 rhythm gets faster and faster, the sounds get closer together.
** Your description of the rhythm of the pendulum when tilted 'forward' **
The sounds get further apart and the rhythum gets slower. It starts off at an ok pace and then the sounds die off when the pearl can no longer reach the bracket.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I placed the bracket on my desk; which is flat.The pearl was barely touching the bracket and I then pulled it back and released it. The rhythum was much more constant with this experiment. The sounds were steady. The pearl hit the bracket 7 times.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
When the pendulum was swinging towards the bottom of the book the sounds got further apart and the rhythum became slower and slower. The pearl only struck the bracket a few times.
When I rotated the bracket 45 the rhythum became a little more steady but still rather slow.
I rotated the bracket another 45 degrees; the bracket was parallel with the book. The pendulum swung in almost a circular motion making the sounds steady and constant.
I rotated another 45 degrees and the pendulum had to swing upward to the top of the book. The rhythum was fast and the sounds got closer together.
I rotated the bracket another 45 degrees to where the bracket was parallel with the top and bottom. The rhythum was once again more steady and the sounds more constant.
I then rotated the bracket one more time and the pendulum swung so that the rhythum was a bit quick..
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
The most steady rhythum came when I rotated the bracket to where it was parallel with the top and bottom of the book.
** Your report of 8 time intervals between release and the second 'hit': **
.502,.574,.551,.514,.539,.574,.633
.622,.621,.619,.610,.601,.599,.567
.677,.689,.678,.655,.645,.633,.629
.588,.599,.567,.545,.532,.545,.510
.522,.577,.566,.545,.534,.567,.512
.619,.677,.656,.643,.642,.621,.623
.678,.677,.654,.699,.625,.655,.677
.599,.615,.625,.655,.643,.644,.679
Every second Hit;
.622,.615,.677,.619
.597,.617,.620
.610,.600,.612,.615
.588,.617,.614
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
The above results show how many seconds it takes for the pendulum to hit the bracket every two hits. the numbers are very up and down.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
14.25 cm.
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.029, .033,.031
** Your description of the pendulum's motion from release to the 2d hit: **
One, because the pendulum only reaches the extreme point one time when it is released.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
Twice, because the pendulum reaches the release point twice, and then it is preveneted from reaching the other extreme point when it hits the bracket. The pendulum has slowed a bit because of the bracket.
** 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: **
I guess that the pendulum cannot hit the extreme point from which it was released because it has lost momentum from hiting the bracket, but if every swing counts then the pensulum reaches the extreme point twice.
** 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 pendulum is losing momentum so it will soon come to a rest. The extreme point lowers each time.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
Because the pendulum is losing momentum and eneergy each time it strickes the bracket.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
They would decrease.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
In this experiment the length was not the only deciding factor. The fact that the pendulum was prevented from reaching the other extreme point affected it. The bracket prevented the pendulum from swinging fully.
** **
2 hours
** **
&#This looks good. Let me know if you have any questions. &#