Define Gas in Harmonic Well?

A classical system of N distinguishable no interacting particles of mass m is placed in a three-dimensional harmonic well:

a) Discover the partition function and the Helmholtz free energy.                                       

b) Concerning V as an external parameter, discover the thermodynamic force P^~conjugate to this parameter, put forth by the system find the equation of state and compare it to that of a gas in a container with rigid walls                                            

c) Find the internal energy, entropy, and total heat capacity at constant volume.