A centrifuge is used to separate white blood cells, red blood cells, and blood plasma by rotating the sample at a high angular speed. Suppose that a sample of blood is placed in a test tube and is swung in a circle of radius 0.0375 m at an angular speed of 360 rad/s. A picture of the test tube at a certain instant is shown below. The mass of the blood and tube (combined) is 0.0069 kg.

Figure: A sample in a centrifuge.

There are only two forces acting on the tube, the gravitational force on the tube and the force by the holder on the tube. Define the system to be the tube and blood sample together. What is the force by the holder on the tube at the instant shown.