How Do I Calculate the Vertical Force Needed to Pull a Copper Ball in Fluid?

[FalcoAtl]

It asks to find the vertical force needed to pull the ball in an unknown fluid at a constant velocity. What formulas do I combine and use to find this? They give you the proportionality constant (0.95 kg/s), the constant speed (6cm/s), and the radius of the ball(1.5cm). I already have:

F (y direction)= F-(mass)(gravity)-Constant(V)

I found mass from the density and volume. The proportionality constant was given as was the velocity.

So... F=(mass)*(gravity)-Constant(V)

Is this right? Because I haven't been able to find the correct answer using it.

 

[Tide]

It is unclear what you mean by F(y direction) and F. Define your terms.