1. The problem statement, all variables and given/known data A 4.50x10^5kg space platform is speeding up from 2.300x10^3m/s to 2.600x10^3mls because a rocket fires with a thrust of 138kN in space. How long must the rock fire to do this? 2. Relevant equations F=ma F=ma+mg 3. The attempt at a solution I have tried to find acceleration so I could find the time. I have attempted to use the equation F=ma+mg to isolate for a but could not.