Resumen de How to use a candle to study sound waves

P. Simeao Carvalho, E. Briosa, M. Rodrigues, C. Pereira, M. Ataíde

• It is well known that sound waves in air are longitudinal waves. Although teachers use analogies such as compressing horizontal springs to demonstrate what longitudinal waves look like, students still present some difficulty in understanding that (1) sound waves correspond to oscillations of air particles, and (2) there is no �air flow� (transport of particles) in sound waves.1,2 These difficulties arise from the impossibility to actually �see� air particles moving, and from the common sense idea that free particles always have translational motion.