1. The problem statement, all variables and given/known data A ball of mass 522 g starts at rest and slides down a frictionless track. It leaves the track horizontally, striking the ground. a. at what height above the ground does the ball start to move? 2. Relevant equations I have: mgh=mgh_2+1/2mv^2 which simplifies to: h=h_2+1/2mv^2 3. The attempt at a solution I got: .2+1.25=1.45 I think that 1.45 is right, but I'm a little confused on how I got to that point. Any help is most appreciated. Thanks.