Please Help Problem 5. From E=3/2 R T=E_k=1/2 v^2, where v^2 represents the average value for the square of the velocity v 1. Explain why the equation relating total energy E to kinetic energy E_k given here is only valid for gases. 2. Determine the average velocity v for argon gas molecules (Ar) in air at room temperature, 298 K. 3. What is the heat capacity at constant volume for Ar per mol? Start with E=3/2 R T (per mol). The heat capacity at constant volume is defined as C_V=d E / d T.