The purpose of the Picket Fence Free Fall Lab was to examine the acceleration of objects as they fall to earth. During free-fall the only force that should be acting upon the object is the earth’s gravitational pull (9.8 m/s/s), therefore the velocity of the object should always equal 9.8 m/s/s. In this lab the picket fence was dropped repeatedly through a photogate connected to Logger Pro, which allowed the fence’s acceleration and velocity to be recorded and graphed.
The results of the experiment confirmed the theory that objects will fall with a constant acceleration equal to g (9.8 m/s/s). During the first 5 runs, the photogate was dropped from the same height and had an average acceleration of 9.762 m/s/s-- which is extremely close to the expected value of 9.8 m/s/s. Even runs during which the photogate was dropped from a higher height or thrown downward (runs 6 and 7), had an average acceleration of 9.741 m/s/s. This proves that none of these circumstances had any affect on the acceleration of the fence and that only gravity influenced its fall. The fence was thrown upward during the last run (run 8) and had an acceleration of -6.470 m/s/s, showing that the force of gravity was slowing it down as it traveled upward.
The results of this experiment were extremely consistent. Out of the first 7 runs, the acceleration only ranged by 0.198 m/s/s. The percent error between the average acceleration in the first five runs and the accepted value for gravity was only -0.388%, and the average acceleration of runs 6 and 7 only had a -0.602% error. Therefore, the data collected was very accurate. We did not experience any major difficulties in the lab other than throwing the fence up through the photogate straight.
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