course phy 201
20090907 2245
Being mostly observed with graphs, will report raw data and results from the 10 foot (~300 cm) ramp. vvvv
Sections covered (cm), Oscillations (.825 s/cycle), clocktime, velocity, ave acceleration
300 cm, 10.5, 8.66 s, 34.64 cm/s, 4 cm/s(squared)
270 cm, 10, 8.25 s, 32.72 cm/s, 3.97 cm/s(squared)
180 cm, 8, 6.6 s, 27.27 cm/s, 4.13 cm/s(squared)
120 cm, 6, 4.9 s, 24.24 cm/s, 4.90 cm/s(squared)
You don't say how you got velocities or accelerations. Your accelerations seem to have been calculated by dividing average velocity by time interval, which is not correct.
Note that the word 'velocity' needs an adjective.
However your acceleration results are reasonably consistent, and when you correct your calculations the accelerations will be different but will be equally consistent.
Observing the average acceleration shows the inaccuracy in the raw data. The outlying number, 4.90 cm/s(squared), helps make this assumption. A pendulum with a .825 second oscillation was used to try to avoid this inaccuracy but did not seem to suffice. However, using a longer pendulum length would of also made the results less accurate and may of ended up with similar data (with this same experiment). This uncertainty is mostly to blame on human error and less on the setup of the experiment. The experiment wasn't setup to observe accuracy in raw data, but precision on the first recording of each trial. Other small features to look at (in the setup), is the evenness of the floor on which the ramp laid, the correct positioning of the ramps on top of the dominoes, the same amount of dominoes removed after each rail (30 cm ramp) installed, and the cut of the edges of the rails. Human error is most due to recognizing when the ball was released and when it reached its end point. Being able to count the pendulum may of also been a human error (since such a small pendulum was used). Overall the data collected is decent but could improve.
Your discussion of errors and precision is very good.
See my notes. You need to clarify how you obtained your results, and in some cases you need to correct your calculations. Once you see what you did wrong it should be easy to make the corrections.