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 sounds get closer as the motion slows down.
** Your description of the rhythm of the pendulum when tilted 'forward' **
It only stikes once because it is at a different angle and the ball is very heavy. (Mine is a magnetic ball so that may be skewing the bounce rate.)
** Your description of the process used to keep the rhythm steady and the results you observed: **
I put it on a level surface (a desk) and tilted it forward slightly so that the ball was hanging. The rhytm was more steady than before because it did not stick to the magnetized bracket.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
The sounds get further apart when I place it on the book. This is probably due to the orientation of the bracket. The sounds seemed to follow the pattern: further, closer, further for each repective 45 degree rotation.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
To get the most regular beat of the pendulum, I would try to place the pendulum on a flat surface. This would help because the sounds would be less skewed due to a change in incline.
** Your report of 8 time intervals between release and the second 'hit': **
.453125
2.21875
.640625
2.6875
.78125
4.34375
.59375
2.3125
.609375
2.3125
.53125
2.296875
.6875
2.234375
.53125
These intervals vary between a little over two and around .5 for every other interval. This is representative of the first swing of the pendulum and recording when the second hit lands. I obtained these numbers by clicking the mouse at the release and once again when the second hit occured.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
2.421, 2.140, 2.25
1.859, 1.703, 1.593, 1.578
1.953, 1.53, 1.5, 1.546
1.828, 1.406, 1.390, 1.343
These results show the intervals from each second hit to the next. I repeated this for four trials to try to get more accurate results.
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
The length of the pendulum is approximately 9 millimeters.
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
The time elapsed between release and 2nd hit: .375, .39, .5
your intervals between release and 2d 'hit' appear to avearage around .6 seconds; the intervals you report here are significantly shorter than that.
The time elapsed between 2nd hit and 4th hit: .875, .859, .906
The time elapsed between the 4th hit and the 6th hit: .843, .625, .953
** Your description of the pendulum's motion from release to the 2d hit: **
The motion between the release and the first hit is like a downward pendulum swing. The hit marks the equilibrium point, which signifies the marble being stopped from going to its other extreme point.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
It is similar to the motion between the release and the first hit, but it is a smaller swing. This is because the wall it hits makes the swing slow down, causing the distance it covers to slow down as well.
** 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 between the release and second hit is faster and covers a larger area than the motion between the second hit and the fourth hit.
** 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 second hit and the fourth hit is faster and covers a larger area than the motion between the fourth hit and the sixth hit.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
We expect that the first time interval should be shorter than the subsequent time intervals because the pendulum is swinging faster because it has more force than it does after the ball hits the wall.
If the pendulum is set up so that the rhythm of the 'hits' is regular, then the time intervals should be uniform, within the limits of experimental uncertainty.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
We expect the time intervals to increase, because the pendulum is swinging slower and therefore it takes more time for the ball to hit the wall.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
The evidence is against this hypothesis because various factors come into play to determine the length of the pendulum's swing, such as the height at which you begin your release, the interval you are counting, etc.
** **
It took me about 45 or 50 minutes to complete the experiment.
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&#Your work looks good. See my notes. Let me know if you have any questions. &#