What happens to the vertical velocity of an object as it travels through the air?

When an object is thrown or moves through the air, its vertical velocity undergoes changes primarily due to the acceleration caused by gravity. Here's a more detailed explanation:

1. Initial Velocity: When an object is initially thrown upward, it starts with a positive vertical velocity.

2. Effect of Gravity: As the object ascends, the force of gravity acts downwards on it with an acceleration of approximately $9.81 \, \text{m/s}^2$. This deceleration reduces the object's vertical velocity over time until it reaches its peak height.

3. Peak Height: At the peak of its ascent, the vertical velocity becomes zero before the object starts its descent.

4. Descending Phase: When the object starts to fall, gravity accelerates it downwards, and the vertical velocity increases in the negative direction (which is often considered downward).

5. Terminal Velocity: Eventually, as the object continues to fall, it might reach a terminal velocity where the force of gravity is balanced by the drag force from air resistance. At this point, the vertical velocity remains constant.

In summary, as an object travels through the air, its vertical velocity first decreases to zero (when moving upward), then increases in magnitude (when falling downward) until it potentially reaches terminal velocity, where it levels off.