A sample of blood is placed in a centrifuge of radius 19.0 cm. The mass of a red blood cell is 3.0 10-16 kg, and the magnitude of the force acting on it as it settles out of the plasma is 4.0 10-11 N. At how many revolutions per second should the centrifuge be operated? I converted 19cm to .19m and then tried using F[c]=m*v(squared)/r but got the wrong answer. Is there a different formula I should be using or did i miss something else? Thank you!!