1, Feng, a musician of nature, will play his accordion in the forest.
When he turned the leaves, the leaves sang different songs like singers. Different leaves have different sounds; Different seasons, different music. When the breeze blows, the voice is soft and gentle, like a whisper, which makes people feel the gentleness of nature; As soon as the wind blew, the whole forest became excited and played a magnificent movement together. The sound is full of power, which makes people feel the power of nature.
2. The sound of the stream
The stream flows down the winding valley, sometimes urgent and sometimes slow. When the stream flows down the high slope, it splashes clouds of water mist. The stream is clear and transparent, and you can clearly see the sand and stones at the bottom of the stream.
Animals are singers of nature.
Walking in the park, listening to the chirping birds in the trees; Sitting under the tree, listening to the buzzing insects; Take a walk by the pond and listen to the song of slugs. Do you know what they are singing? Their songs seem to tell us: "I'm singing and I'm happy!" " "
4, cicada singing
The male cicada keeps singing every day to lure the female cicada to mate. To the female cicada, the male cicada sounds like a wonderful music. After mating and fertilization, the female cicada pricks a row of small holes in the branches with a sword-shaped ovipositor and lays her eggs in the small holes. A few weeks later, both male and female cicadas died.
5. Ray
The air in the lightning passage suddenly rises sharply, making its temperature as high as 15000-20000℃, thus making the air expand rapidly, and the air pressure near the passage can be increased to above 100 atmospheric pressure. Then, it cools rapidly, the air shrinks rapidly and the pressure drops. This sudden expansion and contraction occur in a short time of a few thousandths of a second, so at the moment of lightning explosion, a shock wave will be generated.
The shock wave propagates in all directions at the speed of 5000 m/s, and in the process of propagation, its energy decays rapidly, while its wavelength gradually increases. 0. 1-0.3 seconds after lightning, the shock wave evolves into sound wave, which is the thunder heard.