Which of the following represents a type of explosion?

Mechanical explosions occur when an object or vessel containing a compressed gas, liquid, or solid experiences a rapid release of energy, resulting in an expansion that creates a shockwave or blast. This type of explosion can happen due to various factors, including failure of equipment, excessive pressure, or the rupture of containers. For example, a pressure vessel that exceeds its design limits may rupture, leading to a mechanical explosion, causing potentially devastating effects in the surrounding area.

In the context of the other choices, barometric refers to atmospheric pressure changes rather than an explosion. Thermal explosions involve rapid heating and expansion but are not categorized as mechanical in nature. Radiant generally pertains to the emission of energy such as heat or light, rather than a physical explosion. Thus, mechanical explosions are specifically identifiable by their nature of rupturing physical structures under pressure, making them distinct in their classification.