** Power and Efficiency Definitions **

##### Power and Efficiency Definitions

- Define Shaft Power, fluid power, volumetric efficiency and overall efficiency.
- Calculate values in a fluid power system utilizing Pascalâ€™s law.
- Calculate flow rate, flow velocity and mechanical advantage in a hydraulic system.
- Learn and understand principles of fluid mechanics and power with applications.
- Provide the student the necessary analytic skills to solve and analyze a variety of fluid mechanics and fluid power related problems.

**Mechanical Power** is the rate of doing work. It is equivalent to an amount of energy consumed per unit time. In the MKS system, the unit of power is the joule per second (J/s), known as the Watt in honor of James Watt. Larger units are 1KW = 1000 W or 1 Horsepower (HP) = 746 W.

**Electric Power** in watts produced by an electric current I consisting of a charge of Q coulombs every t seconds passing through an electric potential (voltage) difference of V is: \[P = V \times I = \dfrac{V^2}{R} = I^2 R\] Where,

P = Electric power in Watts

t = time in seconds

I = electric current in Amperes

V = electric potential or voltage in Volts

Mechanical Power, \(P = \dfrac{dU}{dt} = \bar{F} \cdot \bar{v}\)

Mechanical Efficiency, \(\eta = \dfrac{P_{out}}{P_{in}} = \dfrac{U_{out}}{U_{in}}\)