course PHY 201
9:12 PMxxxx
Sunday, August 30, 2009 " "Make a pendulum and count the cycles that occur in a minute at two lengths, one short, one medium and one long. Record the length (e.g, by tracing the short pendulum on your paper, by measuring the medium pendulum against your textbook, etc.).
My Response:
Short: 124 cycles/min
Med: 56 cycles/min
Long: 32 cycles/min
Time things with the pendulum:
* Time a marble down a one-nickel incline using the short pendulum.
* Time a marble down a one-nickel incline using the long pendulum.
* Time a marble down a nickel-dime incline using the short pendulum.
* Time a marble down a nickel-dime incline using the long pendulum.
My Response:
I may have things a bit differently than asked for in this document but hopefully my data will still be relevant. I didn't have a nickel or dime handy so I utilized a domino and a washer, timed with a book-length pendulum:
Domino w/ big marble: 2 cycles
Domino w/ small marble: 4 cycles
Domino + washer w/ big marble: 1.5 cycles
Domino + washer w/ small marble: 2.75 cycles
Domino on side w/ big marble: 1.05 cycles
Domino on side w/ small marble: 2.125 cycles
Tall domino w/ big marble: 1 cycle
Tall domino w/ small marble: 2 cycles
Can you distinguish between a one-nickel incline and a nickel-dime incline using the short pendulum?
My Response:
There was a noticeable difference between each change in the incline.
Can you distinguish between a one-nickel incline and a nickel-dime incline using the long pendulum?
My Response:
We timed everything with a book-length pendulum, but I'm certain there would still be a noticeable difference, though less pronounced with the longer pendulum.
What is the percent difference between 5.5 and 8?
My Response:
Percent difference = |new value - old value| / |old value| * 100
= |8 - 5.5| / |5.5| * 100
= 2.5 / 5.5 * 100
= 0.4545 * 100
= 45.45%
What is the smallest possible percent difference you think you could detect, using the pendulum, in the times required for the ball to travel down two ramps?
My Response:
Perhaps 10-15%."
&#Good responses. Let me know if you have questions. &#