Two masses, A and B, are connected to a rope. A constant upward force 86.0N is applied to box A. Starting from rest, box B descends 12.1m in 4.70s . The tension in the rope connecting the two boxes is 32.0N.
What is the mass of B? What is the mass of A?
My work and what I am struggling with:
I am trying to find the acceleration experienced by B, with that I will find the mass. I find the acceleration using: $$2\Delta_y/t^2=a$$ $$a=1.0955m/s^2$$
Then I have a problem for B do I use this equation: $$\sum F_y =32-M_b*g=M_ba$$ $$Or$$ $$\sum F_y =86-M_b*g=M_ba$$