Acoustic standing waves

In acoustic levitation a standing wave is generated by a piezoelectric crystal which gives rise to a stationary acoustic radiation force. In Physics Education, acoustic levitation furnishes an effective and straightforward method to localize the nodes of acoustic standing waves and to highlight some interesting physical phenomenologies. In the present work two mechanical models to study the damped oscillations of an acoustically levitated sphere are introduced. The work is addressed to graduate Physics, Engineering and Mathematics students.