[单选题]
Sound waves in water travel approximately 4.5 times faster than in air. Which of the following diagrams correctly shows the wavefronts of sound as they pass from air to water?
A.
B.
C.
D.
参考答案: C
本题详细解析: Explanation:
Sound travels faster in water. According to Snell's law, the waves will refract away from the normal as seen in options $A$ and $C$.
Because $v=fλ$ and $f$ is constant across the boundary, favelength also increases when the speed increases as seen in choices $B$ and $C$.
