The SI unit of mechanical power is :

In physics, power is defined as the rate at which work is done or energy is transferred [1]. The International System of Units (SI) designates the watt (W) as the standard unit for power. One watt is equivalent to one joule per second (1 J/s), representing the expenditure of one joule of energy over a duration of one second [1]. This unit applies across various domains, including mechanical systems, where power is calculated as work divided by time. While the joule is the SI unit for energy, and the newton-second is the unit for impulse, the watt specifically measures the rate of energy conversion. The unit was named in honor of James Watt for his contributions to mechanical engineering [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > What you have learnt > p. 192