Power

The rate at which energy is transported or converted, or the rate at which labour is performed, is referred to as power. It is the quantity of work completed per unit of time in technical terms. Watt (W), or joules per second (J/s), is the SI unit of power. Horsepower (Hp), which is roughly equal to 735.5 Watt , is sometimes used to describe the power of motor vehicles and other machines.

Power is a scalar quantity, meaning it provides us with a quantity or amount of energy consumed per unit of time but no indication of direction.

Power Formula

As previously stated, power refers to the rate at which work is performed on an object. Power is a time-based metric that refers to how quickly a task is completed. The following is the power formula:

Power=WorkTime

P=WT

SI Unit of Power

Watt is the SI unit of power (W). One watt is equivalent to one joule of energy transferred in a second.

1 Watt=1 J/s=kgm2/s2

Since the metric system is divided into base units and derived units, we get (kgm2/s2) when we convert joules to base units. This is the formula for converting watts into base units.

Watt is named after an 18th-century inventor named James Watt. By his name, he had invented and patented a number of significant devices. The stream engine is the most well-known of his inventions. Horsepower was used as a unit of power before Watt became the SI unit of power. However, because horsepower is such a massive quantity, the watt was created to provide a smaller unit of power.

1 Horsepower=735.499 Watt

Interestingly, James Watt was also the one who coined the term “horsepower.”

The relationship between power units:

1kW=103W

1MW=106W

1GW=109W

The unit of power in the MKS system is:

kgm2/s-3

The erg per second is the power unit in the CGS system.

In various fields of science and engineering, power must be quantified. Watt has a lot of submultiples and multipliers to make things easier.

Some Submultiples of Watt

Some Multipliers of Watt

Some Multipliers of Watt

Some other units of power and their value

Horsepower(Hp)=746W

British Thermal Unit(BTU)=1Watt=9.47×10-4 BTU

Foot Pounds= 1Watt=0.737 foot pounds

Calories per second= 1Watt=0.24 calories per second

Measurement of Variable Power

To measure variable power 3 methods are used:

• Instantaneous Power – This is the power as measured at a specific point in time. High-level mathematical equipment is required to calculate such power.
• Average power – When power is measured over a lengthy period of time, the average of the results can be determined. You may calculate the average of power by adding the power at several points in time and then dividing the sum by time.
• Peak Power – Peak power is the largest amount of instantaneous power a machine or system can achieve over a lengthy period of time. Peak power is substantially higher than ordinary power, yet it is only sustained for a limited time in order to minimise damage.

Some Important points based on Unit of Power

The rate at which energy is transported or converted, or the rate at which labour is performed, is referred to as power.

• Watt is the SI unit of power; 1Watt=1 J/s=1 kgm2/s-3
• 1 watt equals one joule of effort completed in 1 second.
• Watt is named after James Watt, a well-known inventor.
• Watt is a scalar quantity, which means it doesn’t have any direction.
• The formula of power is Power=WorkTime ; P=WT
• The unit of power in the MKS system is kgm2/s-3

• The erg per second is the power unit in the CGS system.

Conclusion

Work is done in physics when a force acting on an object causes it to move. The time it takes the force to generate the displacement has no bearing on the amount of work done. The task may be completed fast at times, or it may be slow and take longer at other times. If a bodybuilder and a sixth-grader both carry a 10 kg weight up a flight of stairs, the bodybuilder will most likely finish the job faster than the sixth-grader. The bodybuilder, in this case, has a greater power rating than the sixth-grader.