Therefore, every second, the velocity of the ball increases by 9.80 meters per second. Newton's Three Laws of Physics An object continues in its initial state of rest or motion with uniform velocity unless it is acted on by an unbalanced, or net external force. The acceleration of an object is inversely proportional to its mass and directly proportional to the net external force acting on it.
Forces always occur in pairs.
When a bat hits a ball, it gives the ball some of its momentum so that it can fly away. While in the air, the ball experiences the force of gravity pulling downward and the force of air.