PHY 201
Your 'pendulum counts in-class' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
** **
Report one line per observation. Each line should consist the length of the pendulum being observed, the 1-minute count and the scale factor by which your reported length should be multiplied to get the length of the pendulum in centimeters. The three requested quantities should be separated by commas. Each line should therefore consist of three numbers, separated by commas. Don't include any words, units, or other information in any of these lines.
You may report as many lines as possible. Use the space below.
Your data report (start on the next line):
20.5,64,1
41,46,1
82,32.5,1
Add your description of how you made your observations. Include an explanation of how much uncertainty there was in each observation, and explain how you arrived at your uncertainty estimate.
Your explanations (start on the next line):
I began the experiment by laying the pendulum along the length of my hand so that the center of the pendulum (sm. washer) was at the tip of my middle finger, and the end of the string was at the first crease of my right wrist. I then laid the pendulum of this length along a meter stick and measured the centimeters to be 20.5 (thus the multiplication factor above of 1, since I measured in cm to begin with). Once this was obtained, I made a note in my notebook, multiplied it by 2 to get the next pendulum length (41 cm), and then multiplied that by 2 to get the third pendulum length (82cm). I timed the first pendulum using a digital kitchen timer, counting full oscillations (cycles... not half-cycles) until the timer beeped. This resulted in a count of 64 cycles. I counted the succeeding pendulums in similar fashion, arriving at values of 46, and 32.5 cycles. To find the degree of uncertainty, I took the value of my count and subtracted from it the value of a similar count (or rather, my count plus however much I though might be in error and then subtract the actual count and divide by the actual count). I would estimate a degree of uncertainty with the short pendulum to be (64 - 63) / 64 = 1.6% and at the long pendulum to be (32.5 - 32) / 32.5 = 1.5%. The degree of uncertainty is about the same in each case.
&#Your work looks very good. Let me know if you have any questions. &#