2-Mar-2015. Sparker Free Fall Lab.

Purpose: To prove that in the absence of all other external forces except gravity, a falling body will accelerate at 9.8 m/s^2.

Experiment: Using the sturdy column (Picture 1), a free-fall body is held at the top by an electromagnet is released and as it falls, its fall is precisely recorded by a spark generator. The marks made at the intervals on the spark-senstive tape attached to the column create a permanent record of the fall.

(Picture 1)

 The series of dots on the paper corresponding to the position of the falling mass are each in 1/60th of a second intervals. We placed a two-meter stick next to the tape, lining up the 0cm mark with one of the dots from the beginning.

Recorded position of the free-fall body (Picture 2)

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After recording the distance from the 0cm to the next dot, we got a table of data representing the Time vs Distance (Picture 3).

(Picture 3)

The graph of this data is represented below: 

We then made another column that represented the ∆x, the next column was the mid-interval time, and then we used these two new columns to make third column of velocity. 

We then graphed velocity versus mid-interval time to create a scatter graph with a trend line's slope that represented the acceleration. 

The picture shows our resultant calculation of gravity being 9.6218m/s^2 (the slope m in the y=mx+b equation). 

We then recorded the entire classes' gravity results from everyone's experiment to find the standard deviation of the experiment, therefore analyzing the reliability of the experiment. 

The first column values represent the different results from each experiment. The next columns show the manipulations required to result in a 0.2 m/s^s standard deviation in finding gravity.  

The results prove that the experiment is not the most reliable in finding gravity, since the results varied so much.