1. The problem statement, all variables and given/known data I was doing d and had a question because I believe my response is perfectly acceptable but yet it does not reflect the scoring guidelines at all. By the way I believe this is free response #2 on the 2006 Form B AP Physics B test http://img692.imageshack.us/img692/2172/problemf.jpg [Broken] 2. Relevant equations I answered using the coefficient of restitution. I use it all the time when I'm asked for the type of collision http://img709.imageshack.us/img709/995/coefficentofrestitution.jpg [Broken] click on link and zoom in once to read what the coefficient of resitution is if you do not know what it is 3. The attempt at a solution Here's my response http://img688.imageshack.us/img688/4104/myresponse.jpg [Broken] Here's the scoring guidelines http://img706.imageshack.us/img706/5879/scoringm.jpg [Broken] so my question is how would my response be scored? My response is not wrong at all it is as AP would put it "Alternate Solution" as I often see on scoring guidelines. I do not if AP likes people using e when responding to problems of momentum but it's a perfect valid solution... so what do you think??? how would my response be scored?