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 rhythm gets faster as the pearl bounces. The first few times the rhtthm seemed to remain steady, but the sounds were closer together as the distance the pearl bounced decreased.
Your description of the rhythm of the pendulum when tilted 'forward'
With the bracket tilted forward, the rhythm gets slower as the bead bounces.
Your description of the process used to keep the rhythm steady and the results you observed:
I had the tilt the bracket backwards ever so slightly. The pearl bounced about 12 times and the rhythm was steady enough that I couldn't distinguish a noticable difference by hearing.
Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time:
The following data represents the rhythm of the bead against the bracket for each 45 degree clockwise rotation from the original position. The bracket was initially positioned so that the vertical side pointed toward the top of the book text book.
Initial position: Increased rhythm
+45 degrees: Increased rhythm
+90 degrees: Constant rhythm
+135 degrees: Decreased rhythm
+180 degrees: Decreased rhythm
+225 degrees: Decreased rhythm
+270 degrees: Slightly increased rhythm
+315 degrees: Increased rhythm
Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm:
Pointing the vertical side of the bracket toward the right or left side of the book should produce the most regular beat of the pendulum.
Your report of 8 time intervals between release and the second 'hit':
.703
.766
.641
.703
.719
.766
.719
.781
Your report of 4 trials timing alternate hits starting with the second 'hit':
The string was pulled away from the bracket and released so that the bead would bounce off the bracket. The numbers represent the intervals between every two times the bead hit the bracket.
Trial 1:
.688
.594
.625
.594
Trial 2:
.625
.516
.609
.500
Trial 3:
.609
.609
.563
.531
.531
Trial 4:
.734
.609
.516
.531
.625
The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous):
7.7 cm
Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging:
.664, .582, .578
Your description of the pendulum's motion from release to the 2d hit:
The pendulum is released and swings toward the bracket.
Your description of the pendulum's motion from the 2d hit to 4th hit:
The pendulum bounces off the bracket, swings out before swinging back towards the bracket. This differs from the first hit which had only swung from starting position.
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 bead did not bounce as far away from the bracket in the interval between the second and fourth hit as it did between releasing and the second 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 bead did not bounce as far away from the bracket in the interval between the 4th and 6th hit as it did between the 2nd and 4th hit.
Your conjecture as to why a clear difference occurs in some intervals vs. others:
The 1st time interval should be shorter because it only measures the pendulum as it is released toward the bracket. All other intervals consist of the pendulum swinging away from the bracket and then back toward the bracket.
What evidence is there that subsequent intervals increase, decrease or remain the same:
If the bracket is perfectly level, the intervals should decrease because gravity does not allow the pendulum to return to its original position, but to a position closer to the bracket with each consectutive 'hit'. If the bracket was tilted forward, time would increase and if was tilted backwards, time would decrease.
What evidence is there that the time between 'hits' is independent of the amplitude of the swing?
The dependence of a pendulum's swing upon length was not tested in this experiement. It was seen however that the pendulum's swing is dependent on how far it actually swings. In this experiment, the average time interval between 'hits' decreased as the distance the pendulum swung decreased.
You reported increasing time intervals for some orientations of the pendulum and decreasing intervals for others, with constant intervals at certain positions (e.g., the 90 degree position and somewhere near the 270 deg position).
What bearing, if any, does this have on your reasoning on this problem?
1.5 hrs.
However do see my one note and respond.
Please respond by just copying this question, your responses and my comments into a text document and inserting your explanation. As my comments are set off by double asterisks **, set off your inserted comments using &&. Just submit a copy using the Submit Work form. You are of course welcome to also submit additional questions if you have them.