Downward acceleration is independent of mass during free fall
DOI:
https://doi.org/10.64804/h4k7fv51Keywords:
free fall, acceleration, kinematics, cricket ball, ping pong ball, tennis ball, Tracker, gravity, ggplot2, dplyr, RAbstract
This experiment tests Galileo’s theory of free fall by investigating whether or not an object’s acceleration downward is dependent on its mass. Three objects of differing masses were released at rest from a height of about 5 m: a ping pong ball, a tennis ball, and a cricket ball, a mass range of three orders of magnitude. Drops were filmed and tracking software was used to record the position of each object. Position data was then used to create the graphs for velocity-time. The velocity-time graphs appeared linear with slope near −9.8 m/s2 , close to the accepted gravitational acceleration near Earth’s surface. Since the accelerations of each object are consistent with each other to some degree of uncertainty, we conclude acceleration is independent of mass.
References
Aristotle, Physics, Book IV (350 BCE).
G. Galilei, Discorsi e dimonstrazioni matematiche, intorno à due nuoue scienze attenenti alla mecanica & i movimenti locali (1638).
P. Machamer and D. M. Miller, Galileo Galilei, https://plato.stanford.edu/entries/galileo/ (2021).
D. E. Barth, 6.3 Galileo’s falling bodies (2020).
P. A. Tipler and G. Mosca, Physics for Scientists and Engineers, 5th ed. (W H Freeman and Company, New York, 2004).
W. Moebs, S. J. Ling, and J. Sanny, University Physics, Vol. 1 (OpenStax, Houston, TX, 2016).
R. A. Pelcovits and J. Farkas, Barron’s AP Physics C Premium (Kaplan North America, Fort Lauderdale, FL, 2024).
D. Brown, R. Hanson, and W. Christian, Tracker video analysis and modeling tool (2025), version 6.3.3.
J. Renika, E. C. Prima, and A. Amprasto, Kinematic analysis on accelerated motion using Tracker video analysis for educational purposes, Momentum Physics Education Journal 8, 23 (2024). DOI: https://doi.org/10.21067/mpej.v8i1.8883
D. S. Starnes, J. Tabor, D. Yates, and D. S. Moore, The Practice of Statistics, 5th ed. (W. H. Freeman and Company, 2015).
R Core Team, R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing, Vienna, Austria (2025).
H. Wickham, ggplot2: Elegant Graphics for Data Analysis (Springer-Verlag New York, 2016). DOI: https://doi.org/10.1007/978-3-319-24277-4_9
H. Wickham, R. François, L. Henry, K. Müller, and D. Vaughan, dplyr: A Grammar of Data Manipulation (2026), R package version 1.2.0.
D. A. Faux and J. Godolphin, Manual timing in physics experiments: error and uncertainty, American Journal of Physics 87, 110 (2019). DOI: https://doi.org/10.1119/1.5085437
R. K. Hetzler, C. D. Stickley, K. M. Lundquist, and I. F. Kimura, Reliability and accuracy of handheld stopwatches compared with electronic timing in measuring sprint performance, Journal of Strength and Conditioning Research 22, 1969 (2008). DOI: https://doi.org/10.1519/JSC.0b013e318185f36c
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Data Availability Statement
Data are available at https://www.desmos.com/calculator/gkq8zwbfji?authuser=1 and https://github.com/devangel77b/427tchung-lab1
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