Here's the question I'm working on.
A baseball with a mass of 0.152kg is moving horizontally at 32.0 m/s [E], when it is struck by a bat for 0.00200 seconds. The velocity of the ball just after the collision is 52.0 m/s [W 20° N].
Find the impulse experienced by the ball and the average net force of the ball.
I have found the solution to be that the net force is 6292 N in the direction [W 12.4 N].
But I have a conceptual question: Why is it [W 12 N] if the resultant velocity after collision is [W 20 N]?? That doesn't make any sense! Why is it [W 20 N] when it has been affected by a net angle force of [W 12 N].
Imagine a ball rolling on a plane from left to right with constant speed. It's direction is $(1,0)$ (or $[E]$, if you prefer). Then nudge this ball from below - the direction of the force is $(0,1)$ (or $[N]$). What will happen the ball? It will continue to roll with velocity in the first quadrant ($[NE]$).
More conceptually, the force is the change of momentum per unit of time, therefore the direction of the force does no reflect the direction of the momentum itself, only of its evolution.