Understanding the Concepts
* Newton's First Law of Motion: An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
* Gravity: The Earth exerts a downward force on all objects near its surface. This force is called gravity.
Applying the Concepts to the Ball
Since the ball is flying through the air at low speed with negligible air resistance, the only significant force acting on it is gravity.
* The force of gravity is constant: It's always pulling the ball downward.
Conclusion
The net force acting on the ball while it's in motion is the force of gravity, which acts downwards.
Important Note: If the ball were thrown upwards, the force of gravity would still be acting downwards, but the ball's upward motion would be slowed down by this force.
