十万个为什么·科学启蒙30篇（2）

29 / 30

已读 0 / 30 课

为什么声音在水中比在空气中传播得更快？

Sound travels as vibrations that move through particles in a medium like air or water.
Water molecules are packed much more tightly than air molecules, so energy transfers faster.
In air at 20°C, sound moves at about 343 meters per second.
In seawater, sound travels at approximately 1,500 meters per second—over four times faster.
Temperature, pressure, and salinity all affect how fast sound moves underwater.
Whales use low-frequency sounds to communicate across hundreds of kilometers in oceans.
Sonar devices send out sound pulses and measure echoes to map underwater terrain.
Unlike light, sound bends—or refracts—when moving between layers of different water temperatures.
This bending allows sound to travel long distances along ocean 'sound channels'.
That is why submarines can detect each other from far away using passive sonar.

听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。

Temperature, pressure, and salinity all affect how fast sound moves underwater. 温度、压力和盐度都会影响声音在水下的传播速度。
In air at 20°C, sound moves at about 343 meters per second. 在20°C的空气中，声音传播速度约为343米/秒。
Whales use low-frequency sounds to communicate across hundreds of kilometers in oceans. 鲸类利用低频声音在海洋中相距数百公里进行交流。

这篇中文题目最接近哪一句？为什么声音在水中比在空气中传播得更快？一次学校运动会的通知一份超市购物清单

课文第一句的意思更接近？声音以振动形式传播，依靠空气或水等介质中的粒子传递。今天学校放假了。请把窗户打开。

这一课主要在讲什么？（看英文标题） Why Does Sound Travel Faster in Water Than in Air? How to cook noodles A maths worksheet

Temperature, pressure, and salinity all affect how fast sound moves underwater.

Temperature, pressure, and salinity all affect how fast sound moves underwater.

第一版：录下来、回听、再听标准音。系统打分以后再加。

用今天的表达，自己说一句。

例子：Temperature, pressure, and salinity all affect how fast sound moves underwater.