A firecracker tossed into the air

x component of speed =  x cos 60 = 30      reveals  x = initial speed = 60 m/s

now the path the firecracker follows is given by

    x = 60 cos 60   t  = 30 t

    y = 60 sin 60  t        (this ignores the effect of gravity.....for this short period  t  .....to make much simpler calculations )

Using distance formula      15²   = (30t)2  + (30 sqrt3 t)²

                                                  15^2 = 900t^2 + 2700 t^2

                                                    t = 1/4 sec                  in 1/4 second the firecracker will get this high:    60 sin 60  (1/4) = ~ 13 meters

Extra! Extra! Mathematician tosses firecracker... Projectile Equations explode in his face...