NPY and shot

Accepts: 157
Submissions: 514
Time Limit: 2000/1000 MS (Java/Others)
Memory Limit: 32768/32768 K (Java/Others)
Problem Description
NPY is going to have a PE test.One of the test subjects is throwing the shot.The height of NPY is H meters.He can throw the shot at the speed of v0 m/s and at the height of exactly H meters.He wonders if he throws the shot at the best angle,how far can he throw ?(The acceleration of gravity, g, is $9.8m/s^2$)
Input
The first line contains a integer $T(T \leq 10000)$,which indicates the number of test cases. The next T lines,each contains 2 integers $H(0 \leq h \leq 10000m)$,which means the height of NPY,and $v_0(0 \leq v_0 \leq 10000m/s)$, which means the initial velocity.
Output
For each query,print a real number X that was rounded to 2 digits after decimal point in a separate line.X indicates the farthest distance he can throw.
Sample Input
2
0 1
1 2
Sample Output
0.10
0.99
Hint
If the height of NPY is 0,and he throws the shot at the 45กใ angle, he can throw farthest.