En física, potencia (símbolo P) es la cantidad de trabajo efectuado por unidad de tiempo. Si W es la cantidad de trabajo realizado durante un intervalo de tiempo de duración Δt, la potencia media durante ese intervalo está dada por la relación: La potencia instantánea es el valor límite de la potencia media cuando el intervalo de tiempo Δt se aproxima a cero. En el caso de un cuerpo de pequeñas dimensiones: Donde P es la potencia, W es el trabajo, t es el tiempo. r es el vector de posición. F es la fuerza. v es la velocidad.

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In physics, power is the rate of doing work. It is the amount of energy consumed per unit time. Having no direction, it is a scalar quantity. In the SI system, the unit of power is the joule per second (J/s), known as the watt in honour of James Watt, the eighteenth-century developer of the steam engine. Another common and traditional measure is horsepower (comparing to the power of a horse). Being the rate of work, the equation for power can be written: The integral of power over time defines the work performed. Because this integral depends on the trajectory of the point of application of the force and torque, this calculation of work is said to be path dependent. As a physical concept, power requires both a change in the physical universe and a specified time in which the change occurs. This is distinct from the concept of work, which is only measured in terms of a net change in the state of the physical universe. The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is needed for running because the work is done in a shorter amount of time. The output power of an electric motor is the product of the torque that the motor generates and the angular velocity of its output shaft. The power involved in moving a vehicle is the product of the traction force of the wheels and the velocity of the vehicle. The rate at which a light bulb converts electrical energy into light and heat is measured in watts—the higher the wattage, the more power, or equivalently the more electrical energy is used per unit time.

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