2.9. One-dimensional gas Considerar a one-dimensional gas of N particles, with potential interaction V(x1,x2, . . . ,xN) = −

i

.

a. Discuss the validity of the next-neighbour approximation for this potential.

b. Give a numerical estimate of the gas pressure at z = 1 2π .

c. Compute the mean values of the number of particle per unit length and check the validity of the next-neighbour approximation.