Charlie throws a ball up into the air. While the ball is airborne, which is the greatest force acting on the ball to slow it down?

The greatest force acting on the ball to slow it down while it is airborne is gravity. Here's the step by step explanation:

1. When Charlie throws the ball up into the air, he is applying a force to the ball that propels it upwards. This is known as the applied force.

2. As soon as the ball leaves Charlie's hand, the only significant forces acting on it are gravity and air resistance.

3. Air resistance does play a role in slowing the ball down, but its effect is generally much smaller than that of gravity, especially for objects as dense and small as a baseball.

4. Gravity is a force that attracts two objects towards each other, in this case, the ball and the Earth. It works to pull the ball back down to the ground.

5. As the ball rises and slows down, it's because gravity is pulling it back down, working against the initial force that was applied to the ball.

6. Therefore, gravity is the greatest force acting on the ball to slow it down while it is airborne.