Vertical Motion With Constant Acceleration?

A research balloon of total mass 285 kg is descending vertically with a downward acceleration of 2.7 m/s2. How much ballast must be thrown from the car to give the balloon an upward acceleration equal to 4.2 m/s2, presuming that the upward lift of the balloon does not change.Vertical Motion With Constant Acceleration?
Direct answer --%26gt; 102 kg



Second Law



a1 = 2.7 m/s^2

a2 = 4.2 m/s^2

m1 = 285 kg

m2 = 285 kg - x



F = F



m1a1 = m2a2



(285 kg) * (2.7 m/s^2) = (285 - x) * (4.2 m/s^2)

(769.5 N) = (285 - x) * (4.2 m/s^2)

183.2 kg = 285 kg - x



x = 285 kg - 183.2 kg

x = 102 kg