An energy unit where 1 watt-second equals 1 joule (J), representing the energy consumed or produced by 1 watt of power over 1 second. Commonly used to specify photographic flash energy (e.g., “300 Ws flash”), small energy storage devices, or instantaneous energy calculations. Equivalent to the joule in the SI system and universally used in scientific and engineering fields in China and globally.

An energy unit where 1 watt-second equals 1 joule (J), representing the energy consumed or produced by 1 watt of power over 1 second. Commonly used to specify photographic flash energy (e.g., “300 Ws flash”), small energy storage devices, or instantaneous energy calculations. Equivalent to the joule in the SI system and universally used in scientific and engineering fields in China and globally.