1. A sample of blood is placed in a centrifuge of radius 18.0 cm. The mass of a red blood cell is 3.0 multiplied by 10%u221216 kg, and the magnitude of the force acting on it as it settles out of the plasma is 4.0 multiplied by 10%u221211 N. At how many revolutions per second should the centrifuge be operated?
2. A rotating wheel requires 5.00 s to rotate 26.0 revolutions. Its angular velocity at the end of the 5.00-s interval is 99.0 rad/s. What is the constant angular acceleration (in rad/s) of the wheel?