Problem: A model rocket is launched straight upward with an initial speed of 50 m/s. It accelerates with a constant upward acceleration of 2 m/s^2 until the engines stop at an altitude of 150 m. (Use GUESS method, NO working equation.) a) What is the max height reached by the rocket? Answer: delta x = 308.16 m b) When does the rocket reach max height? Answer: t-up = 8.52 s c) How long is the rocket in the air? Answer: t = 16.45 s I can't figure out this problem at all. I know that I have to use the equation X = X_o t + 1/2at^2. The problem is, I don't know what t is and it's what's being asked in b and c. The equations V = V_o + at doesn't work either because I'm missing t. The equation V^2 = V_o^2 + 2a (delta)X doesn't work either because I'm missing the X which is asked for in A. Please help.