Originally Posted by
Winemaker
That velocity is not achieved from simple acceleration due to gravity. A large component of that is its initial velocity
Lets put some numbers on that claim to see how it smells.
Firstly, lets assume that at the apex of its flight (that point where its vertical velocity IS zero), the rocket motor has finished burning.
The energy in the system is the kinetic energy due to its momentarily horizontally velocity plus the potential energy from having climbed that high.
If it travelled 200km over 30min, horizontal velocity averages 400kmph or 111m/s.
The kinetic energy due to its velocity at the apex is 0.5mv^2, roughly 6.2e3 x m, where m is the mass of the missile with no fuel left.
(the horizontal velocity at the apex won't exactly equal the average velocity but it will be of that order)
The energy in the system when it hits the ground at Mach 2.5 (3087kmph) is 367.6e3 x m
The initial velocity gets it up there but the velocity at impact is very much caused by "simple acceleration due to gravity"