Consider a SAWmodel for the same polymer, but with the ?rst monomer bonded to the wall. (This is the model we treated in class.) How many con?gurations have now been eliminated as a consequence of the wall and what is the resulting entropy of this model? What had a bigger effect upon the polymer statistics, the excluded volume of the polymer or of the wall?

Now consider a SAW model for the same polymer, but now with the second monomer bonded to the wall instead of the ?rst. (This model addresses the question raised in class.) Assuming that the terminal (i.e., ?rst and last) monomers are indistinguishable, how many con?gurations are accessible inthis case?

Now consider N = 2 SAW polymers on the same square lattice in the presence of the wall. Each polymer has n = 3 monomers with the ?rst monomer bonded to the wall. For simplicity, assume that the 2 polymers are distinguishable and that the ?rst monomer is bonded 'higher' up the wall than the second. Calculate the con?gurational entropy for the system if the ?rst monomer of the ?rst polymer is separated by a distance d (i.e., d lattice sites) from the ?rst monomer of the second polymer with d =0, 1, 2, 3, 4, or 5. For d =0, 1, and 2 calculate the probabilities for each different con?guration of the ?rst polymer.