hf=mv^2=3kT
f=3kT/h=3*1.38*10^(-23)*6000/(6.65*10^(-34))=3.7*10^14
m=3kT/v^2=3*1.38*10^(-23)*6000/(3*10^8)^2=2.76*10^(-36)kg
This is the weight of a photon.

Cp:
mCpΔT=1/2*m*(v2^2-v1^2)=3/2*k*ΔT
Cp=3/2*k/m=3/2*1.38*10^(-23)/ 2.76*10^(-36)=7.5*10^12J/(kgK)=7.5*10^9kJ/(kgK)
This is the Cp of a photon.