During a conference I have listened that an employee of an armed force, he has said that when a projectile fired from a gun upwards, it is very dangerous because when the projectile descends downwards it acquires a higher speed than the initial instant that is when the projectile was fired upwards.
In my opinion all this is false if we do not assume in the meantime that there is air resistance (friction) and from what height it is fired. Obviously if the air resistance is zero the initial velocity of the projectile $v_0$ will be equal to the final velocity of the same when it reaches the ground.
For example if $v_0=2$ m/s is the velocity of the projectile when it is fired upwards, the speed of descent $v_d$, for the opinion of this officer, is such that: $$v_0<v_d$$
I simply don't agree because if I was facing a balcony and someone shoots me from the ground at an altitude $h>h_0=0$ it hurts less if the same projectile falls on my head at the time of the descent?