1. The problem statement, all variables and given/known data As a roller coaster car crosses on the top of a 10 m radius hill (the track is underneath the car), its apparent weight is one-half its true weight. What is the car's speed at the top? 2. Relevant equations A=v^2/r F=ma 3. The attempt at a solution I tried saying the weight was .5 and solving for velocity, but I still have a missing # for the Force variable. Where do I go from there?