A simple model of a rubber band is one-dimensional horizontal chain consisting of N linked segments. Each segment can be in one of two possible states: horizontal, with length a, or vertical, with length 0. The rubber band is in thermal equilibrium with reservoir at temperature t.
Determine the exact multiplicity function g(N,n) giving the number of states with precisely n horizontal links?
Determine the exact probability P(n) to find the system in a state with n horizontal links?