text: In a solid, shear stress is a function of strain, but in a fluid, shear stress is a function of strain rate. A consequence of this behavior is Pascals law which describes the role of pressure in characterizing a fluids state. 
  The behavior of fluids can be described by the Navier–Stokes equations—a set of partial differential equations which are based on:
  * continuity (conservation of mass),
  * conservation of linear momentum,
  * conservation of angular momentum,
  * conservation of energy.
  The study of fluids is fluid mechanics, which is subdivided into fluid dynamics and fluid statics depending on whether the fluid is in motion.