*By Own work, original version in German by Sgbeer - File:Pferdestaerke.svg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=35217113*

**What is Power?**

Power is the work done in a unit of time. In other words, power is a measure of how quickly work can be done.

The unit of power is the Watt = 1 Joule/ 1 second.

One common unit of energy is the kilowatt-hour (kWh). If we are using one kW of power, a kWh of energy will last one hour.

**Calculating Work, Energy and Power**

**WORK =**

**W =F * d**

Because energy is the capacity to do work , we measure energy and work in the same units (N*m or

**joules**).

POWER (P) is the

*of energy generation (or absorption) over time:*

**rate****P = E/t**

Power's SI unit of measurement is the Watt, representing the generation or absorption of energy at the rate of 1 Joule/sec. Power's unit of measurement in the English system is the horsepower, which is equivalent to 735.7 Watts.

- http://www.edinformatics.com/math_science/work_energy_power.htm

**Electric Power:**The electric power in watts associated with a complete electric circuit or a circuit component represents the rate at which energy is converted from the electrical energy of the moving charges to some other form, e.g., heat, mechanical energy, or energy stored in electric fields or magnetic fields.

For a resistor in a D C Circuit the power is given by the product of applied voltage and the electric current:

P = V * I

Power = Voltage x Current

*http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elepow.html:*

**Calculating Power in a resistive circuit ( sparkfun):**