From Galileo to Apollo: Analyzing Gravitational Acceleration with MATLAB
Summary
This computational physics activity uses MATLAB to analyze two examples of accelerated motion: a ball rolling down an inclined plane and the Apollo 15 hammer-and-feather drop on the Moon. Students identify object positions in video frames, convert pixel and frame measurements into meters and seconds, create plots, fit polynomial models, and differentiate the models to determine velocity and acceleration.
Keywords: MATLAB, computational physics, motion, velocity, acceleration, polynomial fitting, numerical differentiation, experimental error, lunar gravity, Galileo
Learning Goals
The goals of this activity are for students to understand the relationships between displacement, velocity, and acceleration. They also fit a polynomial model to experimental data. Students use the model to determine velocity and acceleration. The activity also provides historical context about Galileo's inclined-plane experiments and the Apollo 15 demonstration of a falling hammer and feather.
The experiment is implemented as a MATLAB live script that requires no programming.
Context for Use
This activity was designed as a virtual physics laboratory exercise for an online introductory physics course. It is intended for first-year university physics students and should take approximately one hour to complete.
No previous MATLAB experience or specialized technical skills are expected. Students are guided through the process of analyzing video-based motion data, converting measurement units, creating graphs, fitting polynomial models, and interpreting velocity and acceleration.
Although designed for an online laboratory, the activity can be adapted for use as an in-person classroom activity, a computer-based laboratory exercise, or a homework assignment. It could also be divided into shorter sections and completed across multiple class sessions.
Description and Teaching Materials
Gravitational Acceleration MATLAB LiveScript (MATLAB Live Script 1.8MB Sep25 26)
Rolling Ball Data (Matlab .MAT File 56.6MB Sep25 26)
Apollo Experiment Data (Matlab .MAT File 28.1MB Sep25 26)
Activity Follow-up Questions (Acrobat (PDF) 72kB Sep25 26)
Example output from activity (Acrobat (PDF) 2.8MB Sep25 26)
Teaching Notes and Tips
Assessment
References and Resources
Historical and experimental background on Galileo's inclined-plane investigations.
Straulino, S. (2008). Reconstruction of Galileo Galilei's experiment: The inclined plane. Physics Education, 43(3), 316–321.
https://doi.org/10.1088/0031-9120/43/3/012
Background, video, and source information for the Apollo 15 demonstration.
NASA. Apollo 15 Hammer-Feather Drop.
https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_15_feather_drop.html
Primary source describing the hammer, feather, release height, and experimental observation.
Allen, J. P. (1972). Summary of scientific results. In Apollo 15 preliminary science report (NASA SP-289). National Aeronautics and Space Administration.
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720015164.pdf