The horizontal initial velocity is
and the vertical initial velocity is
The horizontal velocity remains the same throughout the bullets flight since there is no acceleration in the x-direction after the bullet is fire. But the velocity in the y-direction is changing because of the acceleration due to gravity. Initially this is downward (in the opposite direction of the vertical velocity) and the velocity as a function of time is governed by the equation: where .
Also the x-position of the bullet is while the y-position is .
So after 1 second the bullet has traveled in the x-direction and in the y-direction. So you might say that the bullet is at the position (90,115.1)
Now the target is moving in both the x and y directions. The speed is constant. so after 1 second the target has moved 90m vertical and 90m horizontal putting its position after 1 second at exactly (90,115.1), which is where the target is.