Stress
Force per unit cross-sectional area, unit = Nm-2 = Pa
Strain
Extension per unit length of a solid when deformed
Elasticity
Hooke’s Law
Elastic Limit
Yield point
Strength
Stiffness
Ductile
Brittle
Elastic materials return to their original size and
shape after a deforming load is removed
Extension of a wire is directly proportional to the
applied force
Maximum load which a body can experience and still
regain its original size and shape once the load has
been removed
Point at which the stress in a wire suddenly drops
when the wire is subjected to increasing strain
Maximum force that can be applied to a material
without breaking
The resistance a material offers to having its
size/shape changed
Materials that can be easily stretched without
breaking
Materials that cannot be permanently stretched and
snap soon after their elastic limit
Extension
Increase in length when a wire or spring is stretched
Young modulus
Stress/strain (assuming limit of proportionality not
exceeded)
Plastic
deformation
Stiffness
constant k
Limit of
proportionality
Ultimate tensile
stress
Deformation of a solid beyond its elastic limit
Force per unit extension needed to extend a wire or
spring
Limit beyond which, when a wire or spring is
stretched, its extension is no longer proportional to
the applied force
Maximum stress that can be applied to a material
before it breaks