Nine Variables
This is a list of nine variables listed in a Table in Sperling.
is stress; it is a component of
is strain
is Young's modulus
is shear modulus
by two different names:
modulus of elasticity in shear
modulus of rigidity
is
is Poisson's ratio
is the coefficient of
viscosity.
is the tensile compliance
is held constant, then the measurement
of strain, 
as a function of time makes it possible to
determine as a function of time.
is the shear strain
is the shear stress
is the unit expansion
is the hydrostatic pressure
