Which of the following statements accurately describes sound waves in air?

Sound waves in air indeed can exhibit the Doppler effect, making that statement accurately describe their behavior. The Doppler effect refers to the change in frequency or wavelength of sound waves in relation to an observer who is moving relative to the source of the sound. This phenomenon can be observed when a moving sound source, like a passing ambulance siren, approaches and then recedes from an observer. As the sound source approaches, the waves are compressed, resulting in a higher frequency (or pitch); conversely, as it moves away, the waves are stretched, leading to a lower frequency. This effect is a fundamental characteristic of wave behavior and applies to sound waves traveling through air.

In contrast, sound waves do not require a liquid medium to travel; they can propagate through gases (like air), liquids, and solids. Additionally, sound waves can indeed travel around obstacles to some extent, bending around them due to diffraction. Temperature variations affect the speed of sound in air; warmer temperatures increase the speed of sound due to increased kinetic energy in air molecules, leading to more efficient wave propagation. Thus, the accurate description highlighting the behavior of sound waves is that they can exhibit the Doppler effect.