1. The problem statement, all variables and given/known data The U-2 was an American spy plane capable of flying up to 21 km high at speeds over 600km/h. Determine the time required for the missile to reach its maximum altitude of the U-2. 2. Relevant equations d=v_i t+1/2 at^2 3. The attempt at a solution d=21000m a=-9.81m/s^2 v_i=0 t=? I dont know how to get time by itself and I have tried using the quadratic formula.