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' **
get closer together
** Your description of the rhythm of the pendulum when tilted 'forward' **
the sounds get further apart
** Your description of the process used to keep the rhythm steady and the results you observed: **
i tilted the bracket so that the pearl was just barely resting on the metal. the pearl hit 13 times
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
the pearl side is closer to the bottom so that the back is propped up. the sounds appear to remain constant. when rotated they appear to still remain constant. when rotated another 45 so that the base of the bracket is parallel with the top and bottom, the beat of the pearl gets closer together.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
i would prop the back of the top of the book up, set the bracet up so that the pearl is closer to the bottom, and rotate it 45 degrees
** Your report of 8 time intervals between release and the second 'hit': **
.359
.344
.406
.406
.391
.359
.375
.391
they were obtained by clicking the start of the timer when the pearl was released, and then clicked again once the pearl hit the bracket for the second time.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
.359, .598, .621, .594, .539, .516
.389, .598, .612, .602, .569, .613
.402, .604, .598, .543, .512
.392, .608, .612, .572, .543, .536
they were obtained by timing every other hit of the bracket, with the first time as when the pearl was released.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
90 mm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
.39, .60, .61
** Your description of the pendulum's motion from release to the 2d hit: **
one interval from extreme point to equilibrium
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
2, equil. to extreme, and extreme to equil.
Right, between 2d and 3d hit; twice this between 2d and 4th hit.
** 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, there are more between the second and fourth
** 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, is the same as between fourth and sixth
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
because there are less intervals
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
expect them to decrease as the ball comes closer to a stop
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
the longer the pendulum, the greater the time interval between hits and the more hits that occur
** **
85 min.
** **
&#Good work. See my notes and let me know if you have questions. &#