What Variables Do I Need to Calculate the Sedimentation Coefficient and Mass?

[Starcrafty]

Hey Guys,
so I am in a jam here... I am working on a question regarding analytical centrifugation. Here is what is given. I am given, the density of the solution, Partian specific volume, frictional coefficeent,and the centrifugation speed in rpm. I am also given a chart of 5 time points and the r of the protein at these timepoints.

From this I am supposed to figure out the sedimentation coefficient, and the mass.
The equations i have are
v=(w²rM(1-Vp))/Nf

where v = velocity, w= angular velocity, r = radius from center, M=molar mass, V = partial specific volume, and p = density of the solution

and

s = v/(w²r) = (M(1-Vp))/(Nf)

where s=sedimentation coefficient, N=avagadros number and f=frictional coefficient.

So i can calculate w from the rpm, however inorder to actually calculate the force and get s I think i need the r can anyone confirm this? because inorder to move forward and calculate M i need s. Maybe I am just missing something here x.x.

Also by plotting the time vs r from the chart in excel i have determined the v

 

[Nino MMP]

by taking the difference in r over the difference in time, is this a valid assumption?Thanks for any help you can give me. Yes, you need the radius to be able to compute the sedimentation coefficient. You can also calculate the velocity from the equation v=(w2rM(1-Vp))/Nf. From the equation, you have all the variables except for the radius which you can get from the given chart. Once you get the velocity, you can then calculate the sedimentation coefficient using the equation s = v/(w2r). After that, you can calculate the mass using the equation M=Nfs/((1-Vp)w2r).