This investigation is based on the famous intermediate axis theorem, often called the tennis racket theorem. This theorem describes why objects with three distinct moments of inertia, around three different axes, have an unstable rotation around the intermediate axis (the axis with the intermediate moment of inertia) while the axes that have the largest and smallest moment of inertia have a stable rotation. This phenomenon can be observed in rotations of everyday objects like tennis rackets and phones. By videotaping rotations of different objects with three distinct moments of inertia around three axes, and visually examining the intermediate axis, one can notice the instability of the intermediate axis compared to the stability of rotations about the other two axes. We mathematically analyzed the motion around three axes using Euler’s equations of rotations, the equations governing the dynamics of a rigid body undergoing rotational motion. We solved the differential equations demonstrating the instability around the axis with the intermediate moment of inertia. This behavior was also simulated in MATLAB using Euler’s equations of rotations. Our graphs of velocity as a function of time for rotation around the three axes, demonstrated and justified the visual observations from the videos. These experimental and computational approaches can lead students to a comprehensive understanding of the intermediate axis theorem.

Given the pressing challenges of climate change caused by human interference in natural systems, the civil engineering industry must adopt more sustainable solutions. One approach is the use of supplementary cementitious materials (SCMs), as cement production is a major source of CO₂ emissions. This ongoing study investigates the use of zeolite as an SCM in pervious concrete. During the summer of 2024, over a dozen pervious concrete specimens were cast with 0%, 25%, and 50% zeolite powder replacing traditional Portland cement. Zeolite, a naturally occurring mineral formed from volcanic eruptions millions of years ago, has been shown to adsorb pollutants and, when used as an SCM, can reduce CO₂ emissions from cement production and potentially increase the material's levels of strength. To assess the impact of zeolite on the mechanical and hydraulic properties of pervious concrete, tests on compressive strength, porosity, and permeability shall be conducted during the Winter 2025 and early Spring 2025 quarters. Results will be shared as laboratory tests are conducted and data is analyzed. The filtration capacity of pervious concrete for different types of pollutants, both with and without zeolite, is a key focus for future phases of this research project.