If you are completely stuck on a problem and find a solution online, do not copy it. Instead, look at the final answer (the equation, not the derivation). Work backwards to see how the units balance and how the variables depend on one another. Then, close the solution and try to derive it yourself.
An official, publicly available solutions manual for Polymer Physics " by Michael Rubinstein and Ralph H. Colby
Would you like worked solutions for a particular problem or a chapter problem list?
A: No. On his UNC course page, Rubinstein typically posts only the homework questions, not the answers. He encourages collaborative learning but expects unique derivations.
Keep in mind that using a solutions manual should supplement, not replace, students' efforts to work through problems on their own.