When an object falls on the surface of earth, it doesn't move down anymore. So it looks like the y-component of the object's velocity is zero. 

As soon as the object hits the surface, the normal force of the earth will cancel out the y-component of the object's force. But, we know that force causes acceleration (`F = ma`). So, in the absence of any vertical force, won't the object still have the vertical velocity that it previously had (uniform velocity)? It just won't have acceleration because the gravitational force will be cancelled out by normal force, but it will still have velocity that it previously had before collision, right?