Which factor does NOT affect thermal inertia?

The correct answer indicates that the color of the material does not impact thermal inertia. Thermal inertia is primarily influenced by a material's ability to absorb, store, and transfer heat, which directly relates to specific heat, thermal conductivity, and absorptivity.

Specific heat refers to the amount of heat required to change the temperature of a unit mass of a substance, while thermal conductivity measures how well heat is conducted through a material. Higher specific heat means the material can store more heat without a significant rise in temperature, and greater thermal conductivity allows for quicker heat distribution throughout the material.

Absorptivity relates to how much radiant energy a material can absorb when exposed to light, impacting its heating and cooling characteristics. Collectively, these factors play a significant role in determining how quickly and effectively a material responds to thermal changes.

In contrast, the color of a material primarily affects its absorptivity and reflectivity but does not directly alter the material's inherent properties that govern thermal inertia in the context of heat storage and transfer.