The average speed of molecules in a gas is given by:

Question

Answer 1

Answer is option (A)

From kinetic theory equation we have

Pressure (P) = 1/3 [m/V]Nc² and so PV = 1/3 [mNc²]

Now the total mass of the gas M = mN, and since r = M/V we can write
Pressure (P) = 1/3 [ρc²]

average speed v = √(3p/ρ)