Answer to Question #76106 in Organic Chemistry for jim

Question #76106

f given a RCF of 5000 and a centrifuge like the one below, how would I find the number of RPM to get the aforementioned RCF, my method is explained below. Rotor diameter=27cm

use the equation RCF=W^2*R/G. When I do this question I get 5753 RPM. I first find the acceleration which= W^2*R by multiplying 5000*9.8= 4900. I then take the square root of the acceleration over the radius (in metres) to get angular velocity (w) in radian per second, which = 602. I then multiply this by 60 and dived by 2 pie to get my answer. But this is not close to any of he possible answers. I think it might be to do with the radius I am using, but from the schematic I get half 27 is 13.5. which seems right.

Expert's answer

https://clinfield.com/how-to-convert-centrifuge-rpm-to-rcf-or-g-force/
RCF or G-force= 1.12 x R x (RPM/1000)²
5000=1.12*135*(RPM/1000)^2
RPM=5750