Assume that the collisions with a side are elastic (no energy loss), and thus the velocity component of the ball parallel to each side remains unchanged. Also, assume the ball has a radius of zero. Remember that, unlike pool tables, billiard tables have no pockets.
Input is terminated by a line containing five zeroes.
100 100 1 1 1 200 100 5 3 4 201 132 48 1900 156 0 0 0 0 0
45.00 141.42 33.69 144.22 3.09 7967.81
Source: Waterloo
Local Contest Jun. 19, 1999
根据动量守恒,球无论碰撞多少次,其与水平方向的夹角(只算锐角)不变,则可知球总共在水平方向移动距离a*m英寸,垂直方向移动距离b*n英寸。
#include<stdio.h> #include <cmath> #define PI acos(-1) int main(){ double a,b,s,m,n,agl,v; while(~scanf("%lf%lf%lf%lf%lf",&a,&b,&s,&m,&n)&&a&&b&&s&&m&&n) { agl = atan((b*n)/(a*m))*180/PI; v = sqrt(b*n*b*n+a*m*a*m)/s; printf("%.2lf %.2lf\n",agl,v); } return 0; }
原文:http://www.cnblogs.com/shenchuguimo/p/6358100.html