1. The problem statement, all variables and given/known data http://mediocre.wordpress.com/2008/01/09/newtons-law-of-restitution/ Shown in my blog, link provided. 2. Relevant equations Newton's Law of Restitution, v2 - v1 = e (u1 - u2) 3. The attempt at a solution I have done the question, actually...but I need confirmation. Can anyone please help me to check whether the no.2 hint is correct or not? (Located at the bottom of the post) Thanks in advanced.