Speed of Tayfun missile questions
The only data we have in our hands of this missile is the fact that it flew for 458seconds the distance of 561km. That gives us an average speed of 3.6 Mach for this missile.
A short range ballistic missile of this ilk gains speed and altitude very quickly and reaches it’s apogee under it’s own power. Then levels off and may travel a short part of mid course under it’s own thrust but when fuel is exhausted, it travels with the momentum it has gained. As it starts to lose speed it starts to dive in towards Earth, gaining speed, since there is almost no significant air drag till about 15000metres. During this dive it reaches hypersonic speeds. As it starts hitting denser atmosphere layers it’s speed decreases. The terminal speed of the missile is governed by the law of terminal velocity. The heavier, the more accute the angle of attack and the more aerodynamic the missile is the higher the terminal speed will be. So if the missile is coming down at near 90 degrees, it’s drag coefficient is close to an aerofoil and it’s empty weight is say 2500kg it should hit it’s target with a speed of 1685m/second = ~5 Mach. But this is for ideal conditions and has a lot of ifs. In reality it could be more like 60-70% of this.