Three closed vessels\[A\], \[B\] and \[C\] are at the same temperature \[T\] and contain gases which obey the Maxwellian distribution of velocities. Vessel contains only\[{{O}_{2}}\], \[B\] only \[{{N}_{2}}\] and \[C\] a mixture of equal quantities of \[{{O}_{2}}\] and \[{{N}_{2}}\]. If the average speed of the \[{{O}_{2}}\] molecules in vessel A is \[{{V}_{2}}\] that of the \[{{N}_{3}}\] molecules in vessel B is \[{{V}_{2}}\], the average speed of the \[{{O}_{2}}\] molecules in vessel C is (where \[M\] is the mass of an oxygen molecule)

• A. \[({{V}_{2}}+{{V}_{2}})/2\]  
• B. \[{{V}_{1}}\]
• C. \[{{({{V}_{1}}{{V}_{2}})}^{1/2}}\] 
• D. \[\sqrt{3kT/M}\]