Physics Problem(Research Balloon)?

A research balloon of total mass 330 kg is descending vertically with a downward acceleration of 0.1 m/s2. How much ballast must be thrown from the car to give the balloon an upward acceleration equal to 0.7 m/s2, presuming that the upward lift of the balloon does not change.Physics Problem(Research Balloon)?
Let F be the upward lift..so m*g - F = m*a =%26gt; F = m*g - m*a = m*(g-a) = 330*(9.8-.1) =

F = 3201N



Now we want a to be upward and = 0.7m/s^2 ...so F - m*g = m*a

F = m*(g+a) so m = F/(g+a) = 3201/(9.8+.7) = 305kg



Therefore 330 -305 = 25kg of ballast must be thrown over