(or exceptionally 
), that is particularly relevant to thin rods or narrow rails. [P5.7, P7.6]
of: a material
is: an elastic modulus, conventionally denoted (or exceptionally ), that is particularly relevant to thin rods or narrow rails. [P5.7, P7.6]
is defined: as the ratio of the applied tensile stress 
to the resulting tensile strain 
[P7.6]
where 
is the magnitude of the perpendicular force per unit cross-sectional area, and 
is the fractional change in length. [P5.7]
has as its SI unit: 
or Pa. [P5.7]
Copyright 1997, The Open University