Human: I want to learn more about the physics of a slinky. Assistant: 
A slinky is an idealized model for a flexible object that moves along a straight line when released from rest. It is characterized by two parameters, the length and mass per unit length, which determine its physical properties. The equations of motion for a slinky are derived from Newton’s laws of motion and depend on the ratio between these two parameters. When the ratio is small, the slinky behaves like a stiff rod, while as the ratio increases, it becomes more flexible. In addition, there is an optimal value of this ratio at which the slinky has the maximum possible speed.