We all know that momentum is conserved in a system. But I am confused of one thing. Suppose we have a system containing a wall with very large mass and a ball and use a classical x-y coordinate axis. If I swing the ball at an angle of 45 degrees from the horizontal, upwards to the huge wall (which is at rest), is it possible for the ball to move in a different direction that isn't collinear to its current direction after collision? Say, after coliding with the wall, can the ball move in the +x direction? Or will it always be bound to move on the on the 45 degree horizontal line? I suspect that if we change the angle of colision, i.e. we rotate the wall, then we can make the ball move in any direction we want. Is this true?