Modulus of resilience is the correct answer.

The modulus of resilience is a material property that measures its ability to absorb energy without undergoing permanent deformation. It is defined as the amount of energy per unit volume that a material can absorb in the elastic range without failure. In other words, it quantifies the material's ability to store elastic energy and recover its original shape after being deformed.

The modulus of resilience is an important parameter in designing materials that are subject to impact or shock loading. It helps engineers understand how much energy a material can absorb before it fractures or undergoes plastic deformation. This information is crucial in selecting materials for applications where high impact resistance is required, such as in the construction of safety equipment, automotive components, and structural elements.

The modulus of resilience can be calculated using the stress-strain curve of a material. It is represented by the area under the stress-strain curve within the elastic limit. The elastic limit is the maximum stress that a material can withstand without experiencing permanent deformation.

To calculate the modulus of resilience, the stress-strain curve is divided into two regions: the elastic region and the plastic region. In the elastic region, the material behaves elastically, meaning it deforms under stress but returns to its original shape when the stress is removed. The energy absorbed in the elastic region is proportional to the area under the stress-strain curve.

The modulus of resilience is given by the equation:

Resilience = (1/2) * Stress * Strain

where Stress is the yield strength of the material and Strain is the strain at the elastic limit.

In conclusion, the modulus of resilience per unit volume of a material is a measure of its ability to absorb energy without undergoing permanent deformation. It is an important property for materials subjected to impact or shock loading and is calculated using the stress-strain curve of the material.