 # Definition of Power in Physics

In physics, Definition of Power is the rate of doing work or of transferring heat, i.e. the amount of energy transferred or converted per unit time. Having no direction, it is a scalar quantity. 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.

## Units

The dimension of power is energy divided by time. The SI unit of power is the watt (W), which is equal to one joule per second. Other units of power include ergs per second (erg/s), horsepower (hp), metric horsepower (Pferdestärke (PS) or cheval vapeur (CV)), and foot-pounds per minute. One horsepower is equivalent to 33,000 foot-pounds per minute, or the power required to lift 550 pounds by one foot in one second, and is equivalent to about 746 watts. Other units include dBm, a logarithmic measure relative to a reference of 1 milliwatt; food calories per hour (often referred to as kilocalories per hour); BTU per hour (BTU/h); and tons of refrigeration (12,000 BTU/h) (source wikipedia)

### What is the definition of power in science?

Power – Scientific DefinitionPower is the rate (energy amount per time period) at which work is done or energy converted. The scientific unit of power is the watt (W), which is equal to one joule (energy amount) per second.

### How do you calculate power in physics?

Power is a measure of the amount of work that can be done in a given amount of time. Power equals work (J) divided by time (s). The SI unit for power is the watt (W), which equals 1 joule of work per second (J/s). Power may be measured in a unit called the horsepower.

### What is an example of power in physics?

A 60-W light bulb, for example, expends 60 J of energy per second. Great power means a large amount of work or energy developed in a short time. For example, when a powerful car accelerates rapidly, it does a large amount of work and consumes a large amount of fuel in a short time.

### What is the power rating in physics?

Electric power and power rating. … Definition: Electrical power is the energy exchanged (received or given) during a second. The power thus reflects the rate and extent with which energy is transferred or converted. 4) Meaning of power rating. The more power rating is high, the more efficiency is high.