pearl pendulum

Your work on pearl pendulum 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 together which is also to say the interval between each sound gets shorter and shorter.

Your description of the rhythm of the pendulum when tilted 'forward'

They get further apart which is to say that the interval between hearing each sound gets longer and longer

Your description of the process used to keep the rhythm steady and the results you observed:

The pendulum was leaning forward a little so I held the back with my hand. This made it pretty level and I counted about 10 sounds before it stopped.

Your description of what happened on the tilted surface, rotating the system 45 degrees at a time:

I set the pendulum on the book with the pearl side facing the top of the book where the dominos are in each corner. The pendulum was slightly leaning back so the sounds were heard faster and faster. I turned the pendulum 45 degrees clockwise and got a similar result but the sound was a little more regular. . When I turned the pendulum 45 degrees clockwise again and release the pearl, the sounds were heard slower and slower. I turned it a 3rd time in the same direction and it was a similar sound as the second try.

Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm:

I found that the most regular beats were on the when the pendulum was facing the left or the right of the book so it was not leaning directly forward or back from the dominos.

Your report of 8 time intervals between release and the second 'hit':

.312

.297

.281

.313

.312

.313

.297

.281

Your report of 4 trials timing alternate hits starting with the second 'hit':

.657, .671, .641,

.578, .641, .625

.578, .578, .640

.531, .625, .641

The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous):

4.75 cm

Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging:

.586, .628, .637

Your description of the pendulum's motion from release to the 2d hit:

It appears to make a slight L shape. What I mean is that when I pull it back it looks like it drops down at first and then goes in a pretty straight line toward the pendulum

Your description of the pendulum's motion from the 2d hit to 4th hit:

It bounces back but not as far as it was started and it just appears to go in a straight line without any sort of L shape. If I release it with any sort of angle it will bounce left and right

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:

Well it appears that pearl travels a further distance from the 1st hit to the second hit then from the second hit to the fourth hit but the sound is fairly constant

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 distance traveled by the pearl is a little shorter: it doesn't bounce out as far as.

Your conjecture as to why a clear difference occurs in some intervals vs. others:

because it travels one less distance. When you start the pendulum you hold it out and it bounces in, back out and back in again (3). But from the 2nd to 4th it bounces out in out in (4). So it would initially seem like the first should take longer

What evidence is there that subsequent intervals increase, decrease or remain the same:

Increase because there would be more distances to cross. But this is not taking into account that the distances are shorter which would equal out the less distance to travel.

What evidence is there that the time between 'hits' is independent of the amplitude of the swing?

It would support this hypothesis. No matter how far I held the pearl from the pendulum the intervals were roughly the same as long as the length stayed the same.