course PHY 201
8/26 10 am
Length of short pendulum: 3.25 inchesNumber of cycles short pendulum completed in 60 secs: 82
Length of medium pendulum: length of textbook, 11.125 inches
Number of cycles medium pendulum completed in 60 secs: 53
Length of long pendulum: approximately 47 inches
Number of cycles long pendulum completed in 60 secs: 30
Number of cycles of short pendulum for marble to roll down ramp: 4
Number of cycles of medium pendulum for marble to roll down ramp: 2.5
When a washer is added to the domino incline of the ramp, the number of cycles of the medium pendulum for the marble to roll down the ramp: 2
Difference in drop spot between domino only incline and domino and washer incline: 1.625 inches
For ramp experiment, a domino laying face down was used in place of a nickel and a washer was used in place of a dime.
Setting up proportions in order to find how long in seconds it takes for the marble to complete the ramp:
Using the short pendulum: 82/60=4/x, 82x=240, x=2.9 seconds
Using the medium pendulum: 53/60=2.5/x, 53x=150, x=2.8 seconds
Using the medium pendulum and adding a washer to the incline: 53/60=2/x, 53x=120, x=2.3 seconds
I would conclude that these results are fairly accurate, as the time arrived at using the short and medium pendulums to time the same ramp are extremely close.
Can you distinguish between a one-nickel incline and a nickel-dime incline using the short pendulum?
Yes, it was relatively easy to tell the difference in pendulum swings using the shortest pendulum
Can you distinguish between a one-nickel incline and a nickel-dime incline using the long pendulum?
It is possible, but it would be very difficult as the marble completes the ramp before a full cycle of the longest pendulum. It would be completely estimation
What is the percent difference between 5.5 and 8?
The percent difference between 5.5 and 8 that I arrived at was 31.25. However, using the formula that Wikipedia suggested I use, I arrived at an answer of 37.037037. To get my answer I found the difference between 8 and 5.5, 2.5 (which in your case indicates the amount of work you did not get done yesterday) and divided it by 8 then multiplied the answer by 100 to get a percentage. Is this correct? Or should I use the formula here:
Wikipedia probably told you to divide the difference 2.5 by the average of 5.5 and 8. This would give you 2.5 / 6.75, which I believe would yield your result.
Either method is correct in the appropriate circumstance. When the two given numbers have equal status, the method given by Wikipedia is the correct choice.
http://en.wikipedia.org/wiki/Percent_difference
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?
Our marble required 2.5 pendulum cycles to make it down the ramp. A fifty percent difference would still take more than one pendulum cycle, which would be possible to observe. I’d guess that any more than that, say a 60% difference, would be too quick to time by the same pendulum.
Walk down the sidewalk at constant velocity while someone times you with a pendulum of appropriate length. Can they verify that you walked at constant velocity?
Yes, to some degree. My steps approximately timed with the pendulum swings.
Walk down the sidewalk, increasing your velocity gradually while someone times you with a pendulum of appropriate length. According to their results, did you speed up at a constant, an increasing or a decreasing rate? According to your perceptions, did you speed up at a constant, an increasing or a decreasing rate?
According to both of our perceptions, I sped up at an increasing rate.
How much do you have to change the position of the bottlecap to succeed?
1.625 inches, using the center of the first bottlecap and the center of the moved bottlecap to measure.
Does this exercise distinguish the effect of one thin dime? It definitely does, as it shows that even an extremely slight difference in incline affects where the marble will land on the ground.
The difference that the change in incline made in proportion to the change it made in the landing spot of the marble is very interesting.
&#Your work looks very good. Let me know if you have any questions. &#