Acoustic and high speed video analysis of exploding gas filled balloons

Acoustic and high speed video analysis of exploding gas filled balloons Michael B Muhlestein Department of Physics and Astronomy Bachelor of Science Exploding gas-filled balloons are common chemistry demonstrations. They provide an entertaining and educational means to experimentally verify nonlinear acoustical theory as described by the Earnshaw solution to the lossless Burgers equation and weak-shock theory. This paper describes the theory, the demonstration, and the results of a propagation experiment carried out to provide typical results. Data analysis shows that an acetylene-oxygen balloon produces an acoustic shock whose evolution agrees well with weak-shock theory. On the other hand, the pressure wave generated by a hydrogen-oxygen balloon also propagates nonlinearly, but does not approach N-wave-like, weak-shock formation over the propagation distance. High-speed video of these explosions provide discussion material on directionality of propagating acoustic shocks. Overall, the experiment shows that popular demonstrations of chemical reactions can be extended from chemistry classrooms to a pedagogical tool for the student of advanced physical acoustics.