When an object is thrown upward, the initial velocity is the velocity at the moment of release or the instant it leaves the thrower's hand. The final velocity is the velocity of the object when it reaches its highest point and starts descending.
The initial velocity is typically positive because it is directed upward. However, for the sake of simplicity, let's assume we're considering a scenario where the object is thrown vertically upward with an initial velocity of v0.
At the highest point of its trajectory, the object momentarily comes to rest before starting its descent. At this point, the final velocity is zero (0 m/s) since the object momentarily changes its direction of motion.
So, in summary:
Initial velocity (v0): Positive and represents the velocity of the object at the moment it is thrown upward. Final velocity: Zero (0 m/s) at the highest point of the object's trajectory.
Once the object starts descending, its velocity becomes negative (directed downward) as it gains speed due to the acceleration due to gravity.