1. The problem statement, all variables and given/known data A research balloon of total mass 220 kg is descending vertically with a downward acceleration of 4.3 m/s2. How much ballast must be thrown from the car to give the balloon an upward acceleration equal to 0.8 m/s2, presuming that the upward lift of the balloon does not change. HINT: One body with two situations again. Draw sepatate FBD before and after the ballast is thrown out. Two equations from two FBDs. 2. Relevant equations F=ma 3. The attempt at a solution I don't know what forces I need to plug in which formula.