云朵为什么不会从天上掉下来?它是什么做的?
Why dont clouds fall from the sky? What are they made of?
云朵是无数比灰尘还小的小水滴集合成的,每一颗都轻得像空气。它们被上升的暖风托着,像羽毛飘在空中。等水滴抱在一起变得又大又重,托不住了,就变成雨点落下来——那是云在下雨呢。
Clouds are crowds of droplets tinier than dust, each light as air. Warm rising winds hold them aloft like floating feathers. When droplets hug together growing heavy, they fall as raindrops — the cloud is raining.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版地球分册,少年儿童出版社,2013
Ten Thousand Whys: Earth volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#云 #雨 #天气
先看见闪电后听见雷声,是闪电跑得慢吗?
Why do we see lightning before hearing thunder — is lightning slow?
恰恰相反,光和雷声同时出发,只是速度天差地别:光每秒约跑三十万公里,声音每秒只走约三百四十米。看到闪电就数秒,数出的秒数乘以三百四十米,大约就是雷电离你的距离。记住:只要能听见雷声,雷电就可能伤到你,要尽快进屋躲避。
Quite the opposite — flash and thunder start together but race at wildly different speeds: light covers about three hundred thousand kilometers per second while sound manages only about three hundred forty meters. Count seconds after the flash and multiply by three hundred forty to gauge how far away the storm is. Remember: if you can hear thunder, lightning is close enough to hurt you — get indoors fast.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版地球分册,少年儿童出版社,2013
Ten Thousand Whys: Earth volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#雷电 #声速与光速 #安全距离