When a solid object is subjected to a tension
force, T on both ends it will stretch by a distance
denoted AL. A quantity called the strain,
denoted by & is the distance stretched, AL
divided by the original length of the object, Lo,
i.e. & = AL/Lo. For many materials, the
applied tension force is measured to be linearly
proportional to the strain times the cross-
sectional area, A of the object i.e.
ΤαεΑ
The figure shows an object with a circular cross-
section of diameter d and original length Lo. If
object 2 has twice the diameter and twice the
starting length of object 1 (and is made of the
same material), what must be the ratio T₂/T₁ so
that the two objects have the same strain.