Final answer:
A material under plane stress conditions is expected to fail at higher loading than that of a plane strain because plane stress conditions involve forces acting in two dimensions, whereas plane strain conditions involve forces acting in three dimensions.
Step-by-step explanation:
In the context of stress and strain, a material under plane stress conditions is expected to fail at higher loading than that of a plane strain. This behavior is expected because plane stress conditions involve forces acting in two dimensions, whereas plane strain conditions involve forces acting in three dimensions. The additional dimension of force in plane strain makes the material more susceptible to failure.