Electrical Power:

You may decide to spare yourself the tiring work of cranking a winch to lift heavy objects over and over now to perform experiments to elaborate the nature of power. Anyway, it is hard to measure mechanical power directly, though it can be computed theoretically.

You may connect an electric motor to the winch, as shown in figure below. If you then connect a wattmeter among the power source and the motor, you can measure the power directly. Obviously, this supposes that the motor is 100 % proficient, along with the other assumptions that the rope does not stretch and the pulley has no friction. All these assumptions are, obviously, not envoy of the real world. A real pulley does have friction, a actual rope will stretch, and a real motor is less than absolutely proficient. As an outcome, the reading on a wattmeter connected as shown in figure would be greater.

Figure: Electrical power can be measured directly whenever a motor is used to drive a winch to lift a heavy object