1. The problem statement, all variables and given/known data When venturing forth on Planet X, you throw a 5.24kg rock upward at 13.0 m/s and find that it returns to the same level 1.51 s later. What does the rock weigh on Planet X? 2. Relevant equations W=m*a 3. The attempt at a solution To find the acceleration i good the 13.0m/s / 1.51s = 8.61 m/s^2. W=5.24kg * 8.61 m/s^2 = 45.1 N The online hw keeps telling me that my answer is wrong. What am I doing wrong? Thank you for the help!