2021年7月20日河南省遭受特大暴雨表击,因灾死亡失踪398人.郑州日降雨量
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E7%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
, 其中最大小时降雨量达
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
, 通常说的小雨、中雨、大雨、暴雨等,一般以日降雨量衡量,指从天空降落到地面上的雨水,未经蒸发、渗透、流失而在水面上积聚的水层深度.其中小雨日降雨量在
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmtext%3E1%3C%2Fmtext%3E%3Cmtext%3E0%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
以下;中雨日降雨量为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E%7E%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
;大雨日降雨量为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmo%3E%E2%88%BC%3C%2Fmo%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
;基雨日降雨量为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmo%3E%E2%88%BC%3C%2Fmo%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
;大暴雨日降雨量为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmo%3E%E2%88%BC%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
;特大暴雨日降雨量在
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmtext%3E2%3C%2Fmtext%3E%3Cmtext%3E5%3C%2Fmtext%3E%3Cmtext%3E0%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
以上,为研究宜春某天降雨量,某同学自制一个高为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
的无盖正四棱柱形容器底部镶嵌了同底的正四棱锥形实心块,如图1所示,接了24小时的雨水(不考虑水的损耗),水面刚好没过四棱锥顶点
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EP%3C%2Fmi%3E%3C%2Fmath%3E)
, 然后盖上盖子密封,将容器倒置,如图2所示,水面还恰好没过点
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EP%3C%2Fmi%3E%3C%2Fmath%3E)
, 则当天的降雨的级别为( )
![](http://tikupic.21cnjy.com/2022/04/22/a3/49/a349ed6b159367073b0c5608caf5fd29_336x275.png)