1. The problem statement, all variables and given/known data A stationary uranium-238 nucleus undergoes alpha-decay. What is the ratio of the daughter nucleus to that of the alpha-particle? P.S. It's a practice problem for which I had the final answer, but I'm not sure how to reach it. 2. Relevant equations I guess it's based on conservation of energy. I'm unsure of the equations, though. 1/2 mv^2 for K.E. 3. The attempt at a solution Sorry, I just don't know how to start.