In an amusement park ride called The Roundup, passengers stand inside a 15.9 m diameter rotating ring. After the ring has acquired sufficient speed, it tilts into a vertical plane (a) Suppose the ring rotates every 4.5 s. If a rider's mass is 69 kg, with how much force does the ring push on her at the top of the ride? How much force the does the ring push on her at the bottom of the ride? I tried to use Min. Force of Gravity = mv^2/r I ended up with 8.82 m/s for velocity and I solved for the 3rd question (not included) but I'm not sure what to do with these two problems.