Natural Frequency for Torsional Vibration of Fixed Fixed Beam

Hi All:

I am trying to calculate natural frequency for torsional vibration of fixed fixed beam using following formula in US system.

=1/2*3.142 sqrt(K*g/mr^2) hz

Where K=J*G/L

and G=Modulus of rigidity

g=acceleration due to gravity=386.4 in/se2

m=mass hanging on the beam at distance 'r' from the longitudenal axis

My question is how does the equation above (if its right) is affected if I change the beam from fixed fixed to fixed -free.

thanks