Imagine the Earth to be an extended body, spinning about an axis. Suppose we throw a ball vertically upwards. As soon as the ball leaves our hand, it starts traveling upward with some velocity and also with some angular velocity, equal to that of the Earth, just before it was thrown. However, as soon as the ball leaves our hand, we can consider it to be a Kepler orbit. As it moves upward, due to the conservation of angular momentum, its angular velocity should decrease, as distance increases. Let's say, the ball rises to a height $h$. At ground $0$, it had an angular velocity $\omega_g$, and at height $h$ it has an angular velocity $\omega_h$ such that $\omega_h \lt \omega_g$.
Since the earth is an extended object, if we project the longitudes on the surface of the Earth, at the height $h$, they would have the exact same angular velocity as the ground, as in extended circular motion, the angular velocity remains the same, as the points are still completing one revolution in 1 day.
Hence the ball lags behind the longitudes at this height, while rising and falling down again, as it has an angular velocity always less than that on the ground.
Is this the reason, why balls get deflected sideways when thrown upwards ? Is this the reasoning behind the vertical coriolis effect?