Aroom contains air in which the speed of sound is 343 m/s. the walls of the room are made of concrete, in which the speed of sound is 1 850 m/s.

(a) find the critical angle for total internal reflection of sound at the concrete–air boundary.
(b) in which medium must the sound be traveling in order to undergo total internal reflection?
(c) "a bare concrete wall is a highly efficient mirror for sound." give evidence for or against this statement.

2.which choice most accurately explains what happens to the bonds between atoms when water changes to steam, and what becomes of the energy added during this phase change? when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms.