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Just as this baseball is being struck there will be the force the bat exerts on the ball and then there will be gravity as well, gravity being straight down, and after the ball is in the air it will have only gravity exerting a force on it assuming there is no air friction. So if in a diagram while our ball is in the air is this, despite the fact the ball is moving probably this way that motion does not matter the diagram tells you the forces only and shows that the acceleration is downwards. So it’s a projectile, we were doing a projectile motion here.