What is the unit of power known as?

Power is defined as the rate at which work is done or energy is transferred over time. The unit of power in the International System of Units (SI) is the watt. One watt is equivalent to one joule per second, meaning that if one joule of energy is used in one second, the power is one watt. This relationship highlights how power quantifies the speed of energy conversion or work performance.

The other units mentioned relate to different physical concepts: a joule is a unit of energy, a newton is a unit of force, and a volt is a unit of electric potential difference. While all these units play crucial roles in physics, it is the watt that specifically measures power, making it the correct choice in this context.