1. The problem statement, all variables and given/known data A swing is rotates with the distance 5m to the center of rotation. A full 360 degree rotation is possible. Find the minimal value of the velocity at the highest point, so that the person operating the swing doesn't fall. Given data: r = 5m 2. Relevant equations Downward accelaration: x = 0.5 * -9.81 * t^2 3. The attempt at a solution So that someone never falls from the swing, then the accelaration upward should be 9.81 m/s^2, but at the highest point (x = 0m, y = 5m), there isn't any vertical velocity. Because there is no velocity, the derivative from the vertical velocity at the highest point is 0, meaning that the downward accelaration is greater than the upward accelaration, meaning that the person would fall if not properly secured. What am I missing here?