In a drought affected region she may be required to carry it over large. The rate at which energy is transferred is called power and the amount of energy that is usefully transferred is called efficiency. Energy onpage 157 we dealt with power arid noted that power is the rate at which energy is transferred from one place to another or from one form to another the formula that links energy and power is. Work done is measured in joules which has symbol j. If the puck slides twice as far, the friction does twice as much negative work. Work done by the force is equal to the product of the force and the displacement of the object in the direction of force. Class 11 physics revision notes for chapter 6 work, energy and power free pdf download. Work, energy and power definition, units, formula, examples. In the equation the mass is measured in kilograms and speed in ms.
When the pendulum is released, the potential energy is converted into kinetic energy as the pendulum bob descends under the i nfluence of gravity. Work formula example of work types of energy power formula questions. Understand the use and limitations of the bernoulli equation, and apply it to solve a variety of fluid flow problems. Cbse class 11 physics work, energy and power formulas. P power watts, w, js u voltage volts, v i current amperes, a r resistance ohms. For example, potential energy in the compressed spring, kinetic energy in the moving object, electromagnetic energy and heat are some of them. Kinetic energy is energy associated with motion, whether in a straight line of a circle. Physics 0303 nonconservative forces and conservation of energy. Note if power is more, work is done fast and vice versa. Work can be used to understand the energy of many objects that experience forces. Work done by the force is positive if the angle between force and displacement is acute 0 feb 09, 2017 work, energy and power formula list and important points in this video, we will revise the topic work, energy and power.
The energy dissipated in 60 seconds can be calculated. Work done w is defined as the dot product of force f and displacement s. A powerful hoist needs energy fuel to keep on working. Energy the capability of doing work is called energy. Energy energy is the quantity that can be used to perform work. Work and kinetic energy formula, definition, equation. One example is the work required to stretch a spring. If youre seeing this message, it means were having trouble loading external resources on our website. Problem set overview this set of 32 problems targets your ability to use equations related to work and power, to calculate the kinetic, potential and total mechanical energy, and to use the work energy relationship in order to determine the final speed, stopping distance or final height of an object.
This is the workenergy theorem or the relation between kinetic energy and work done. Learn science work power formulas with free interactive flashcards. Jul 24, 2018 class 11 physics chapter 6 work, energy and power 03 work energy theorem iit jee neet duration. The kinetic energy of an object can be related to its mass and velocity with the formula, this formula for kinetic energy can be found from the equation for work, if the force is in the same direction as the objects displacement. For formulas, see work done by a constant force parallel to displacement and work done by any constant force, and work done by a positiondependent force. In other words, the work done is equal to the change in k. Work, energy and power class 11 notes physics chapter 6 work is said to be done when a force applied on the body displaces the body through a certain distance in the direction of applied force. Also, we know that when an object in motion strikes a stationary object, it can cause it to move. The unit of energy is the joule, the unit of power is the watt, and the unit of time is the second. Work, energy and power formula list and important points in this video, we will revise the topic work, energy and power. Physics 0302 potential energy and conservative forces. The work w done by the net force on a particle equals the change in the particles kinetic energy ke. When a net force does work on an object, then there is always a change in the kinetic energy of the object.
Free pdf download of physics class 11 chapter 6 work, energy and power formula prepared by subject expert teacher at vedantu. Hvac formulas ton of refrigeration the amount of heat required to melt a ton 2000 lbs. Regarding the work energy theorem it is worth noting that i if w net is positive, then k f k i positive, i. A moving car, walking up stairs, lifting heavy objects, an aeroplane flying, etc are among the most common examples that give us insight into the concept of work, power, and energy. Static friction kinetic friction velocity addition centripetal acceleration. This also means the constraint forces do not add to the instantaneous power. Then the work done by the force is the component of f in the direction of motion.
Work, energy and power formulae work of a constant force. This summarizes most important formulae, concepts, in form of notes of work energy and power which you can read for jee, neet preparation. Chapter 6 work, kinetic energy and potential energy. The power rating energy per unit time of the stove can be calculated as. Physics notes class 11 chapter 6 work, energy and power. Power is the rate at which work is done or energy is transformed. Kinetic energy of an object is its capacity to put another object in motion.
December 1996 subcourse overview this subcourse is designed to teach you to perform work, power and energy calculations for electrical circuits. Choose from 500 different sets of science work power formulas flashcards on quizlet. Distance, velocity, momentum, force, pressure, work and. In other words, the work done on an object is the change in its kinetic energy. Work done is generally referred in relation to the force applied while energy is used in reference to other factors such as heat. It is measured by the product of the force and the distance moved in. Work, energy and power class 11 notes physics chapter 6.
It is important to know whether a force is an conservative force or an nonconservative force in the system, because this is related to whether the force can change an objects total mechanical energy. Physics notes class 11 chapter 6 work, energy and power work when a force acts on an object and the object actually moves in the direction of force, then the work is said to be done by the force. Regarding the workenergy theorem it is worth noting that i if w net is positive, then k f k i positive, i. Power, the rate at which work is done or energy is transferred into or out of the system. Distance, velocity, momentum, force, pressure, work and energy. Derive an equation for the potential energy of a spring, using hookes law and a forcedisplacement graph. This section covers work, energy and power using maths.
Work is said to be done when a force applied to an object moves that. Power can also be defined as the rate of transfer of energy. The further it moves under the influence of your force, the more work you perform. A collision in which the total kinetic energy of the system is conserved is called elastic. If the magnitude of the displacement of the object is labeled x, and this represents the displacement away from an equilibrium position x 0, then the force required to pull the object on the spring to a. Energy cant be created or destroyed, it can only be changed from one type into another type.
It is measured by the product of the force and the distance moved in the direction of the force, i. Work and kinetic energy formula, definition, equation, videos. In the international system of units, the unit of power is the watt, equal to one joule per second. In physics, we can define energy as the capacity to do work. Work w is the energy transferred to or from an object by means of a force acting on the object. Cbse class 11 physics notes chapter 6 work energy and power. There are two types of energy, kinetic and potential. Here are complete work energy and power important notes and summary. Workenergy theorem work, energy and power siyavula. In grade 10, you saw that mechanical energy was conserved in the absence of nonconservative forces. Dimensions of power linear momentum of an isolated system is always conserved in a collision. Work is said to be done when a force applied to an object moves that object.
Solved examples on work, power and energy study material for. If negative work is done, then the object will lose energy. An electric stove consumes 5 mj of energy from a 230 v power supply when turned on in 60 minutes. Doubling the speed quadruples the kinetic energy so the work by friction to reduce the kinetic energy to 0 make it stop must also increase by a factor of 4. Work, energy and power in this section of the transport unit, we will look at the energy changes that take place when a force acts upon an object. Mar 24, 2019 important notes of physics for neet, jee for work energy and power are useful for all aspirants preparing for entrance exams including jee, neet.
You can also call it as revision notes for work energy and power or cheat sheet of work energy and. If youre behind a web filter, please make sure that the domains. Work of a constant force force is parallel to displacement work of force of friction w f x cos w f x w ffric x kinetic energy 2 2 1 ek mv gravitational potential energy near a planet surface ep m g h gravitational potential energy r m m ep g elastic potential energy 2 2 1 ep k x. Work, power, and energy are among the most important concepts of mechanics. Work, energy and power tuesday february 10th reading. The bigger unit of power is kilowatt and represented by kw. In physics, power is the rate of doing work or of transferring heat, i. The ratio of the kinetic energy gained to the work put in to lifting the cars is the efficiency kegpe of the system. Suppose a force f acts on a body, causing it to move in a particular direction. This article deals with the summary of work, power and energy, formulas and how they are related to each other in a crux form which not only clear your concepts but also help in your preparation.
Mathematically, it is computed using the following equation. A woman carrying water from a well to her house is said to be working. Work done by the force is negative if the angle between force and displacement is obtuse 90 work done is negative. A moving car, walking up stairs, lifting heavy objects, an airplane flying, etc are among the most common examples that give us insight into the concept of work, power, and energy. The equation for power can be written as the rate of work. Energy is a key principle in physics, as it allows work to be done. We can calculate work by multiplying the force by the movement of the object. Work, energy and power definition, units, formula, examples, types. Important notes are also helpful for revision when you have less time and have to study many topics. The kinetic energy of an object can be related to its mass and velocity with the formula, this formula for kinetic energy can be found from the equation for work, if the force is. The unit of kinetic energy is the same as the unit of work, the joule j. Using the estimates of kinetic energy from problem 3, calculate the efficiency energy in vs.
The rate at which energy is transferred is called power and the amount of energy that. Energy is the capacity of an object to transform the world which surrounds it. I will start the video by discussing calculation of dot product of two. The engine of your motorcycle works under this principle. Work, power, and energy electrical subcourse number it 0348 edition a us army intelligence center fort huachuca, az 8566000 2 credit hours edition date. Energy transformed work done applied force x distance. These notes are prepared by some of the highly expert teachers. Joule the units of work, equivalent to a newtonmeter. Work, power and efficiency work, power and efficiency aqa. Work done by a force in displacing a body is equal to change in its kinetic energy. Product of force on an object and the distance through. Cascarano formula sheet physics 4a foothill college. The time integral of this scalar equation yields work from the instantaneous power, and kinetic energy from the scalar product of velocity and acceleration.
Work, power and efficiency work, power and efficiency. If positive work is done, then the object will gain energy. Work definition if an object moves in response to your application of a force, you have performed work. Work with the energy equation expressed in terms of heads, and use it to determine turbine power output and pumping power requirements. As is implied by the equation for power, a unit of power is equivalent to a unit of work divided by a unit of time. This is because the object experiences an acceleration and therefore a change in velocity. The force and the displacement must be parallel to one another in order for work to be done. A farmer clearing weeds in his field is said to be working hard. The terms work, energy and power are frequently used in everyday language. Work, energy and power physics neet class topperlearning. There are many forms of energy, each involving both kinetic and potential energy.
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