What distinguishes deflagration from detonation in explosions?

Deflagration and detonation are two types of explosive reactions that are distinguished by the speed at which the reaction wave travels through the explosive material. The correct choice emphasizes that detonation occurs at a speed greater than the speed of sound.

Detonation involves a supersonic reaction wave, meaning it travels faster than sound within the material, which is typically around 343 meters per second (1,125 feet per second) in air at standard conditions. This rapid waveform results in a sharp and intense explosion, producing a shock wave that can cause significant destruction due to the high-pressure front.

In contrast, deflagration is characterized by a subsonic combustion wave that does not exceed the speed of sound. This results in a slower, less intense reaction that spreads through the material at a rate that allows for thermal and pressure waves to propagate gradually.

Understanding the distinction between these two processes is crucial for fire investigators, as it helps them assess the nature and potential hazards associated with explosive materials they may encounter during their investigations. Knowledge of the mechanisms and speed associated with detonation compared to deflagration also aids in identifying the cause of the explosion and in implementing safety measures with sources of explosives.