To solve for the number of revolutions per second, we need to relate the centripetal force experienced by the red blood cell in the centrifuge to the rotation speed. The formula for the centripetal force F6 on an object moving in a circle of radius r' at a tangential speed 1; is: where w is the angular speed in radians per second. Substituting this expression into our centripetal force equation: Fczmw we Given: FE = 4 x 10-11 N m = 3 x 10-15kg 'r' 2 0.16m Plugging in the values: 4 X 10-\": 3 >