Instructions:
Press 'Release' to drop the ball. Use the curser after to measure the heights at equal time intervals.
Explanation:
The equation of motions shows that the y position of a falling object will follow a quadratic time dependance. $$y(t) = y_0 - \frac{1}{2}gt^2$$. You can verify this relationship by measuring the heights at the equally spaced times and plotting the values with respect to time. A parabolic shape should be seen in the x vs. t plot.
Link to stand-alone sim: Here is a link to view the sim on its own, with no distractions.