rotating disc theory

[mastraa]

Good morning.

I was dealing with the theory of rotating discs to make me a small excel of calculation.
to check to do the right things I found this example and I realized I'm wrong. In my opinion it is in the unit of measurement of the angle speed, when I go to make the following calculation of the boundary conditions I get exaggerated values.

Can anyone help me?

Andrea

 

[mastraa]

edit:

I found, there was a wrong conversion on the density. . .

the rotation speed unit is rad/s as 'always'