1. The problem statement, all variables and given/known data Within 4 sec of liftoff, a spacecraft that is uniformly accelerating straight upward from rest reaches an altitude of 450 m [up]. What is the spacecraft's acceleration? 2. Relevant equations The five key equations, plus the velocity, speed, and acceleration equations 3. The attempt at a solution I don't know what the altitude would be (Displacement? Distance?), so I can't solve the equation with the five key equations.