Dropping Speed Science Fair Projects

Ball science fair projects hit the target...

Jason
Grade 7

Objectives/Goals

The purpose of this experiment is to investigate the effect of ball size on dropping speed in viscous liquids.

Methods/Materials

Basically, all that is needed is an assorted number of balls, a stopwatch, glycerin, and a cylindrical container. The container is filled with glycerin, the ball is dropped into the cylindrical container and the speed is timed. The results were then recorded on a table and graph.

Results

The average falling time of the 1.6 millimeter ball was 37.075 seconds, the average falling time of the 3.2 millimeter ball was 10.15 seconds, the average falling time of the 4.8 millimeter ball was 5.335 seconds, the average falling time of the 6.4 millimeter ball was 36.275 seconds, the average falling time of the 7.9 millimeter ball was 2.9375 seconds, the average falling time of the 9.5 millimeter ball was 2.345 seconds, the average falling time of the 12.7 millimeter ball was 2.96 seconds, and the average falling time of the 19.1 millimeter ball was 8.355 seconds. While the balls were being dropped, I found out that small balls left touching the glycerin will sit on its surface tension, allowing more precision on the timing. The results that came out were almost perfect, and were ripe for analysis.

Conclusions/Discussion

My original hypothesis was that the balls falling speed would increase with its diameter. The gain in seconds per 1.6 millimeters would be estimated to be not in definite intervals, but to be somewhat exponential. With the given results, my hypothesis was fairly correct; the larger the ball, the faster it falls, but the hypothesis of how much? was not exactly identical to the results.  3rd party site