解:流速跟水管的橫截面積成反比,跟壓力沒關系。壹二三段面積比為16:4:9。代碼如下
?#include?<stdio.h>main(){
float?pi=3.1415926; float?r1=0.4,r2=0.2,r3=0.3; float?s1=0,s2=0,s3=0,v1=0,v2=4.5,v3=0; s1=r1*r1*pi;? s2=r2*r2*pi; s3=r3*r3*pi; v1=v2*s2/s1;? v3=v2*s2/s3; printf("第壹段的流速為:%.4f?m/s\n",v1); printf("第二段的流速為:%.4f?m/s\n",v3);}