1. The problem statement, all variables and given/known data A person starts from rest at the top of a large frictionless spherical surface, and slides into the water below. At what angle (theta) does the person leave the surface? Then the book gives a "hint": (Hint: The person will lose contact with the surface when the Fn (normal force) is zero.) 2. Relevant equations So I was playing with a few quations and with the gravitational force and its vectors and ended up with Cos(theta)=0, but that would be at 90 deg. and I don't think that's right. 3. The attempt at a solution So, gravity would be the only force acting here, right? So gravity would be causing the motion and the centripetal force, etc.? It's fairly obvious that if the person had remained in contact witht he surface until hitting the 90 deg. mark, the contact would be lost, but, like I said, it seems contact would be lost before that due to accelration from gravity...I can't quite figure how to intertwine everything to find out the velocity and angle, etc... Any help in the right direction would be great, thanks.