hi @greg_n and @SonjaX6.
The formula I deduced is for constant speed (eq. 12). but it derived from the more complex formula that has the solution with constant deacceleration (Eq.08). I tested the constant speed using medium velocity and the results are pretty similar to constant deacceleration. Here is an example closer to reality, modeling deacceleration with aerodynamic drag using the constant speed formula validating at Trump microphone.
disclaimer: the deacceleration is not constant, because the drag is proportional to the velocity squared and because the drag coefficient increases a little depended from Mach number. The correct solution is a logarithmic decrease in speed, but that takes more time to implement a formulation.