Your work on discussion form has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
Item Code
Review
Your Contribution
Review of Answers to Timer Res
I think we have answered the question of the smallest possible resolution of the TIMER program. The smallest resolution seems to be .0039 seconds. There is one smaller number reported as a possible resolution, but I think that the observed interval of .00025 is an artifact from rounding. My reported .0039625 is an error, and should have been .00390625. The formula for finding the intervals between .12 and .19 was meant to be .12 + .00390625x with x from 1 to 17 (I'm student 4).
The data reported by student 3 as all possible intervals between .12 and .19 seems to be a list of reported intervals from the data we submitted. I don't think that we actually recorded every possible interval during our experiments. Looking at the data, though, I see that my calculation for all possible intervals must be incorrect. I only have 17 values, and they do not represent many of the reported intervals. My calculation is probably a list of the smallest number of intervals between .12 and .19.
Student 6 had the same conclusions (correctly expressed) that I did. I think now, though, that in order to get all of the possible intervals we have to include more than just the smallest possible ones. In order to get the next interval from .12 we add .0039. If the resolution of the timer is .0039, wouldn't the interval .1250 also be possible? There should be (and are) values between .1239 and .1278 ( (.0039 *2) + .12). I'm not sure how to include all of them. I think adding multiples of .0039 to all of the possible values between .1239 and .1278 until we reach .19 will give us a complete list.
Your conclusion that .0039 is the smallest possible resolution is very close to being correct. However .0039 is not precise enough. For example the interval from the smallest to the largest reported value is not a multiple of .0039, but of 0.00390625.
0.00390625 is a fraction of the form 1 / n for a certain whole number n. Can you find that number?
Your work on discussion form has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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Review
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Review of Symmetry of Motion
I think we have answered the question of whether motion of a ball down a ramp is symmetrical with respect to right vs left side raised.
For those of us who noted asymmetry in the motion, we also accounted for it (I'm student 4). So we can say that the motion is symmetrical.
Student 2 seems to have the only successfully symmetrical experiment. The intervals are easier to compare if they are comma delimited or on separate lines. Including a representative sample instead of all the data made his report more readable.
Student 6 had an experience similar to mine, where the motion was not symmetrical due to the conditions of the experiment. The intervals are not included, so we can't see how much of a discrepancy there was.
Good review. Thanks.
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Pearl_Pendulum_Amplitude_Depen
My data is not included, I have no pendulum.
I think that the observations recorded when the pendulum was level indicated the pendulum's period. The observations when the pendulum was on a slope indicated intervals that were greater or less than a full swing. I agree that the time between hits will vary based on the slope of the surface the pendulum rests on, but I don't think that's an indication of the period of the pendulum unless we measure the angle and calculate the percentage of a period that the pearl is swinging for. Looking at the observations from the level swings only, it does appear that the period of the pendulum is dependent only on its length.
Good review. I agree with your conclusions.
Your work on discussion form has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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Review
Your Contribution
Review of Uniformity of Angula
My data does not appear on the discussion page. I had to resubmit it on the 26th of June.
Velocity in °/sec for second - longest rotation:
180°/.6975 sec = 261
180°/1.046875 sec = 171
180°/1.234275 sec = 145
130°/2.171875 sec = 60
Acceleration
-86 degrees/sec^2
-21 degrees/sec^2
-39 degrees/sec^2
The velocity is decreasing, but not at a constant rate.
We tried to answer the question of whether or not angular velocity changes at a uniform rate. We were unanimous in finding that angular
velocity decreases, but we were unable to determine that it was at a constant rate. It makes sense that friction is the force that
caused the velocity of the strap to decrease. It would seem that the friction would remain constant, but that is only true if the strap
remained perfectly level during each rotation. That does not seem likely. The placement of the weights and direction of the force
applied to start the motion contribute to how level the strap remains during rotation. Our experimental conditions were not stringent
enough for us to determine whether angular velocity changes at a uniform rate, but were sufficient to prove that velocity decreases at
a decreasing rate.
Student 2 listed their intervals, and concluded that the velocity was constantly decreasing. When I calculated the change in velocity
for the intervals listed, I found that the velocity decreased at a decreasing rate after the second interval but the rate of decrease
was not constant.
Student 6 concluded that the velocity decreased, and that the rate was not constant. No data was included
Thanks for your information and for your reviews, all of which have so far been excellent.