I'm confused with this problem: A baseball is thrown straight upward. What is the ball's acceleration at its highest point? I think that it would be gravity but its speed is 0 right? When problems say that a ball is thrown up with an acceleration of 3 m/s^2, does the acceleration magnitude already include that of gravity? Because if not, wouldn't you need to subtract the 10m/s^2 of acceleration of gravity too?