Phy 121
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' **
I am pretty sure the pearl hit the system at a consistant rhythm.
** Your description of the rhythm of the pendulum when tilted 'forward' **
The time between bounces seems to increase as time goes on with the system tilted.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I put a very thin plastic ruler under the far end of the system. The rhythm seemed very steady and I was getting roughly 9 bounces per release from roughly 45 degrees.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
I started with my pearl hanging towards the bottom, lower end of my book.
At this angle, I got 8 bounces.
I then turned the system 45 degrees right (counterclock wise) and got 4 bounces. I then turned it again 45 degrees in the same direction getting 8 bounces again. On my next 45 degree turn, I again got 4 bounces. The next turn has the pearl facing the top, higher end of the book and I got 8 bounces. I turned it again getting 5 bounces and 2 more times getting respective 8 and 6 bounces.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
I believe slanting the bracket downward slightly gives the bouncing the most regular pattern.
** Your report of 8 time intervals between release and the second 'hit': **
.4062
.2969
.25
.3438
.375
.2969
.2969
.3281
This is two times the time it takes from the max amplitude to hitting the system.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.375, .5156, .6719
.4531, .5, .6406
.4063, .4844, .6875
.4219, .5313, .6563
These are the respective 2nd, 4th, and 6th hits of the pearl against the system.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
7cm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.4141, .5078, .6641
** Your description of the pendulum's motion from release to the 2d hit: **
1
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
2
** 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: **
3, it is 1 less.
** 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: **
4, it is the same.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
It has the most potential energy being converted into kenetic energy to begin with.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
After the 1st potential to kenetic drop, we lose kenetic energy in the form of heat, sound, and to air resistance, so there is not as much kenetic left to convert back to potential.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
This proves that wrong in that we see that the length remains consistant, but swing times change based on the height at the potential energy point.
** **
About an hour and 15min including system construction.
** **
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