physics
posted by sara .
A ball of circumference 71.5 cm and mass 640 g is forced to the bottom of a swimming pool and then released. After initially accelerating upward, it rises at a constant velocity. (The density of water is 103 kg/m3.)
(a) Calculate the buoyant force on the ball.

densityball=mass/volume=.640kg/(4/3 PI r^3)
where radius r= .715/2PI
bouyant force: (mass displaced watermassball)g
= volume(densitywaterdensityball)g
= volume (density water)g  massball*g
= you finish it. Keep units in SI: kg, m^3 
this gives me the answer for drag force

What would the equation for the drag force the ball experiences while it is moving upward at constant velocity be?