1. The problem statement, all variables and given/known data While on planet X, an object is thrown vertically upward with an initial velocity of 5m/s. If this object returns to the point of release in 3s, what is the acceleration of a free falling object on this planet? 2. Relevant equations a=vf-vi/t 3. The attempt at a solution 0-5/3 = -1.6m/s^2 The answer is -3.3m/s^2 in the book...i don't understand how they arrived at that?