How is one watt defined in terms of energy per time?

One watt is defined as one joule of energy transferred per second. This measurement emphasizes the relationship between energy and time, specifically denoting how much energy is utilized or generated over a specific time period. The definition highlights the instantaneous rate of energy transfer or conversion, making it a critical unit in physics and engineering.

In the context of the other options, joules per minute, hour, or day would represent slower rates of energy transfer, thus not aligning with how power (measured in watts) is understood. By focusing on joules per second, the definition not only maintains a clear connection between energy and time but also aligns with the common use and understanding of power in electrical systems and mechanical work.