# power meaning in physics

What does power mean? Work has a specific definition in physics. = e | In physics, power (symbol: P) is how fast work is done or energy is given from one thing to another. d Power, in science and engineering, time rate of doing work or delivering energy, expressible as the amount of work done W, or energy transferred, divided by the time interval t—or W/t.A given amount of work can be done by a low-powered motor in a long time or by a high-powered motor in a short time. The rate at which energy is transferred is called power and the amount of energy that is usefully transferred is called efficiency. Prostitutes, masseurs, gymnasts, beauticians, and so on are known for their manifestation of particular physical powers. The meaning of power: (Power has been discussed in a previous unit and the activity in which the students run up a flight of stairs to measure their power is probably the best way for students to get a real feel for what power means. As power doesn’t have any direction, it is a scalar quantity. ⋅ The maximum power principle or Lotka's principle has been proposed as the fourth principle of energetics in open system thermodynamics, where an example of an open system is a biological cell.According to Howard T. Odum, "The maximum power principle can be stated: During self-organization, system designs develop and prevail that maximize power intake, energy transformation, … Synonym Discussion of power. Unit of power. {\displaystyle W=\int _{C}\mathbf {F} \cdot d\mathbf {r} =\int _{\Delta t}\mathbf {F} \cdot {\frac {d\mathbf {r} }{dt}}\ dt=\int _{\Delta t}\mathbf {F} \cdot \mathbf {v} \ dt}. Power is a scalar quantity. ) F ) Physical strength or force exerted or capable of being exerted: the power of the waves. A 1x magnification power is a 100 percent increase in the magnified object’s size For example, a 1-inch object at 1x would appear to be 2 inches. F {\displaystyle \tau } v In mechanics, the work done by a force F on an object that travels along a curve C is given by the line integral: where x defines the path C and v is the velocity along this path. 2 It is measured in dioptres (inverse metres), and equals the inverse of the focal lengthof the optical device. If a mechanical system has no losses, then the input power must equal the output power. The instantaneous electrical power P delivered to a component is given by. In physics, power is used to describe the rate at which energy is used. By using ThoughtCo, you accept our. ⋅ What Is the Definition of Work in Physics? The rate at which a light bulb converts electrical energy into light and heat is measured in watts – the electrical energy used per unit of time.[4][5]. We are giving a detailed and clear sheet on all Physics Notes that are very useful to understand the Basic Physics Concepts. d F Sometimes the power of motor vehicles and other machines is given in terms of Horsepower (hp), which is approximately equal to 745.7 watts. Though both force and displacement are vector quantities, work has no direction due to the nature of a scalar product (or dot product) in vector mathematics. By Steven Holzner . Learn more. When discussing power, people are usually referring to average power, Pavg. ... Clearly, there are many kinds of physical powers, of which one, the medical, has already been mentioned. Power and how it relates to work and time, how to calculate power and the unit called horsepower. Horsepower is often used to describe the power delivered by a machine. These ratios are called the duty cycle of the pulse train. A 1x magnification power is a 100 percent increase in the magnified object’s size For example, a 1-inch object at 1x would appear to be 2 inches. ∫ s {\displaystyle P={\frac {dW}{dt}}={\frac {d}{dt}}\int _{\Delta t}\mathbf {F} \cdot \mathbf {v} \ dt=\mathbf {F} \cdot \mathbf {v} } v P (a) Calculate the average light intensity of the laser beam. Joule The units of work, equivalent to a Newton-meter. The same difference as distance and velocity. Power is the rate at which work is done or the rate at which energy is transfered from one place to another or transformed from one type to another. . I google a bit and find a web that claims rms power is meaningless without further explanation. Collision Physics Definition: Collision between two or more particles is the interaction for a short interval of time in which they apply relatively strong forces on each other. The SI unit of power is the watt, which is one joule per second. A bulb with a higher wattage will use more electricity per unit of time. ⋅ Electric power is defined as the rate at … Jones, Andrew Zimmerman. ⋅ The power involved in moving a ground vehicle is the product of the traction force on the wheels and the velocity of the vehicle. What is the power at a specific time? 4) Meaning of power rating The more power rating is high, the more efficience is high. Electric power from the definition of power. A tutorial on power that can be applied to AP Physics and other physics courses. Power is one of the key units in many electronic circuits. In everyday life it has a wide range of meanings. physics.fisikastudycenter.com - Learning work and power in 10 common questions and the solutions. So you put it in the standard form for integrals and get (4) Now to integrate. ThoughtCo. P: SI unit: watt (W) In SI base units: kg⋅m 2 ⋅s −3: Derivations from other quantities. Learn more. W P Power is "the ability to satisfy one's wants through the control of preferences and/or opportunities" [Kuhn, 1963, p. 317]. a In Physics, Power is Transfer of Electrical Energy The peak power is simply defined by: The peak power is not always readily measurable, however, and the measurement of the average power ; the power emitted by a source can be written as:[citation needed], Rate at which energy is transferred, used, or transformed, "Electrical Calculations for Rallway Motors", https://en.wikipedia.org/w/index.php?title=Power_(physics)&oldid=995396465, Articles with unsourced statements from August 2017, Creative Commons Attribution-ShareAlike License, This page was last edited on 20 December 2020, at 20:31. Similarly, you will learn about the electric power formula in detail over here. The form of energy is dependent on the frame of reference, and can be transformed into other forms. Definition of power in the Definitions.net dictionary. P Remove the voltage by substituing from Ohm's law. In this case, power can be written as: P W In the end, both cars are going 60 miles per hour, but the 80-hp engine can reach that speed faster. = g Force is a fundamental expression of physical occurrences, as are time and distance. Look at what this gives us. Watt is defined as:”When a body does work of one joule in one second is called its one watt power.” 1 watt = 1J/1S. Although sources such as electric batteries can supply electric power, it is mostly produced by electric generators. For formulas, see work done by a constant force parallel to displacement and work done by any constant force, and work done by a position-dependent force. Power consumption is the amount of input energy (measured in watts) required for an electrical appliance to function.This is opposed to power output which is a measure of the level of performance, of a heat pump for example. = t ⋅ Electric power is a widely used term in physics as you must be aware of. In physics however, it has a very specific meaning. When the unit of time approaches zero, calculus is needed to derive an answer, but it is approximated by force times speed. To give a vague idea, we can describe work as a force applied over a distance. The term "power" is also, however, used to express the ability of a lens or other optical device to focus light. Watt definition physics. ϵ The output power of a motor is the product of the torque that the motor generates and the angular velocity of its output shaft. x ( = v Since work is force times displacement (W=F*d), and velocity is displacement over time (v=d/t), power equals force times velocity: P = F*v. More power is seen when the system is both strong in force and fast in velocity. {\displaystyle \cdot } It makes no difference if the weight is lifted slowly or quickly. Learn about Power in Physics and Electricity with Definition, Unit, Formula, Calculation and Examples. P = Power. t If the current is direct, electronic charge progresses always in the same direction through the device receiving power. For historical reasons, the horsepower is occasionally used to describe the power delivered by a machine. In older works, power is sometimes called activity. ) represents scalar product. Power is the time rate at which work is done. s It is the amount of work done in a period of time (ΔW/Δt) or the amount of energy transferred in a period of time (ΔE/Δt). d In the case of a constant force, work is the scalar product of the force acting on an object and the displacement caused by that force. 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