A interesting modal

REQUIRE "atoms.a4l";
MODEL FallDownFromHigh;
        people_mass              IS_A        mass;
        building_height          IS_A        distance;
        time_falldown            IS_A        time;
        v                        IS_A        speed;
        time_stop                IS_A        time;
        f                        IS_A        force;
        (* equations comes here *)
        BuildingHeight:        building_height = 0.5 *1{EARTH_G} * time_falldown ^ 2;
        Speed: v =  1{EARTH_G} * time_falldown;
        ImpulseConservation: f * time_stop = people_mass * v;
END FallDownFromHigh;