Transformation (reflection and transmission) of sound and electromagnetic waves are considered in non-stationary media, properties of which abruptly change in time. Reflection and transmission coefficients for both amplitudes and intensities of sound and electromagnetic waves are obtained. Quantitative relations between the reflection and transmission coefficients for both sound and electromagnetic waves are given. The sum of the energy flux reflection and transmission coefficients for both types of waves is not equal to one (for sound waves it is greater than one). The energy of both waves is not conserved, that is, exchange of the energy occurs between the corresponding waves and medium. As a result, the sound wave obtains a notable property: the transmitting wave carries energy equal to the sum of the energies of the incident and reflected waves. A possibility of the amplification of sound waves and transformation of their frequencies is illustrated.
ASJC Scopus subject areas
- Condensed Matter Physics
- Statistical and Nonlinear Physics