A pendulum in motion can either swing from side to side or turn in a continuous circle. The point at which it goes from one type
of motion to the other is called the separatrix, and this can be calculated in most simple situations. When the pendulum is prodded at an almost constant rate though, the mathematics falls apart. Is there an equation that can describe that kind of separatrix?
Explanation: Kinematics is a branch of mechanics focusing on describing motion of objects, excluding from consideration the study of forces that act on such objects.