1. The problem statement, all variables and given/known data

2. Relevant equations
[MATH]F=ma[/MATH]

3. The attempt at a solution
I'm having trouble because the original acceleration is positive and the final one is positive. How do I set up the proportion with what I have? Setting [MATH]-305*1.4=m_2*1.3[/MATH] doesn't work.

What is the acceleration of the freely falling balloon?
why the balloon's acceleration is reduced?
What is the net acceleration of the balloon when it is moving up?