Power:
* The rate at which work is being done on/by a system.
* The rate of energy transfer into or out of a system.
Definition:
Average Power
Instantaneous Power 
Units:
SI W = watt = J/s = Joules per second
Other Units:
kW = kilowatt = 1000 W
hp = horsepower = 746 W
Scalar Product Power-Velocity Relationship: 