Differences in Coefficients of Restitution Using Different Data Analysis Methods
Faculty Mentor Information
Dr. Nick Hudyma, Boise State University
Presentation Date
7-16-2026
Abstract
Coefficients of restitution are how much energy is conserved by an object upon collision another object, typically a surface. This is important for rockfalls on soil slopes as falling rocks can prove dangerous to roads. The testing conducted was within a controlled environment and was done with 2 different sized balls, 2 different soil moisturization levels, and 5-6 different drop heights. A high-speed camera was employed to capture the impact and rebound of the ball, additionally a sensor for acceleration was imbedded within the balls. The different methods of data analysis included using software to track a feature of the ball as it fell to gather position data and thus velocity, as well as known and theoretical values of height and final velocity before impact respectively. Using the video tracking proved to be inconsistent at low heights but got better the higher the drop. The other methods proved to be mostly consistent across drop heights with a few outliers. Overall, there was a general trend of decreasing coefficients of restitution which is most likely caused by energy being expended in soil deformation additional photogrammetry was used to analyze the impact craters.
Differences in Coefficients of Restitution Using Different Data Analysis Methods
Coefficients of restitution are how much energy is conserved by an object upon collision another object, typically a surface. This is important for rockfalls on soil slopes as falling rocks can prove dangerous to roads. The testing conducted was within a controlled environment and was done with 2 different sized balls, 2 different soil moisturization levels, and 5-6 different drop heights. A high-speed camera was employed to capture the impact and rebound of the ball, additionally a sensor for acceleration was imbedded within the balls. The different methods of data analysis included using software to track a feature of the ball as it fell to gather position data and thus velocity, as well as known and theoretical values of height and final velocity before impact respectively. Using the video tracking proved to be inconsistent at low heights but got better the higher the drop. The other methods proved to be mostly consistent across drop heights with a few outliers. Overall, there was a general trend of decreasing coefficients of restitution which is most likely caused by energy being expended in soil deformation additional photogrammetry was used to analyze the impact craters.