Question

What is the mechanical unit of power? State it's relation with its SI unit?

Answer 1

Mechanical power is the rate at which work is done. Mechanical power is expressed in units of joules/sec (joules/s) or a watt (W) in the mks system, and feet - pounds force per second (ft-lbf/s) or horsepower (hp) in the English system.
Electrical power, $P=VI=I^{2}R=\frac{V^2}{R}$
S.I unit of power is Watt and commercial unit of power is Horse power.
S.I unit of electrical energy is Joule whereas the commercial unit of electrical energy is kilowatt-hour (kWh).