"the si unit of power is the watt which is equal to one joule per second" in German The SI unit of power is the watt , which is equal to one joule per second. Die SI-Einheit der Leistung ist das Watt , was einem Joule pro Sekunde entspricht. Detailed translations for "the si unit of power is the watt which is equal to one joule per second" The SI unit of power is the watt , which is equal to one joule per second. The SI unit of power is the watt , which is equal to one joule per second. Die SI-Einheit der Leistung ist das Watt , was einem Joule pro Sekunde entspricht.