#include<bits/stdc++.h>
using namespace std;
const double u=3.14159265358979;
const double esp=1e-8;
double v,h,g=9.8;
double f(double x){
	return v*cos((x/180.0)*u)*(v*sin((x/180.0)*u)/g+sqrt((2.0*h*g+v*sin((x/180.0)*u)*v*sin((x/180.0)*u))/(g*g)));
}

int main(){
	int n;
	double x,L,R,mid,maxn,midd;
	while(scanf("%d",&n)==1){
		for(int i=0;i<n;i++){
			L = 0;R = 90;
			mid = midd = maxn = 0;
			scanf("%lf %lf",&h,&v);
			while(R-L>esp){
				mid=L+(R-L)/2;
				midd=mid+(R-mid)/2;
				if(f(mid)<f(midd))
					L=mid+esp;
				else
					R=midd-esp;
			}
			printf("%.2lf\n",f(L));	
		}
	}
	return 0;
}