A mixing beater consists of three thin rods, each 11.0 cm long. the rods diverge from a central hub, separated from each other by 120°, and all turn in the same plane. a ball is attached to the end of each rod. each ball has cross-sectional area 4.10 cm² and is so shaped that it has a drag coefficient of 0.660. the drag force on each ball is r = 1 2 d a v2 where d is the drag coefficient, the density of the fluid, a the cross-sectional area, and v the speed of the object moving through the fluid.