Product of force on an object and the distance through. Mathematically, it is computed using the following equation. Suppose a force f acts on a body, causing it to move in a particular direction. Power can also be defined as the rate of transfer of energy. Static friction kinetic friction velocity addition centripetal acceleration. Work w is the energy transferred to or from an object by means of a force acting on the object.
This is because the object experiences an acceleration and therefore a change in velocity. The unit of energy is the joule, the unit of power is the watt, and the unit of time is the second. Workenergy theorem work, energy and power siyavula. Joule the units of work, equivalent to a newtonmeter. Work, energy and power formulae work of a constant force. 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. 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. Cbse class 11 physics notes chapter 6 work energy and power. The terms work, energy and power are frequently used in everyday language. The unit of kinetic energy is the same as the unit of work, the joule j. Dimensions of power linear momentum of an isolated system is always conserved in a collision.
Here are complete work energy and power important notes and summary. Energy is the capacity of an object to transform the world which surrounds it. Important notes are also helpful for revision when you have less time and have to study many topics. If negative work is done, then the object will lose energy. Work done by the force is equal to the product of the force and the displacement of the object in the direction of force. Free pdf download of physics class 11 chapter 6 work, energy and power formula prepared by subject expert teacher at vedantu. Work done by a force in displacing a body is equal to change in its kinetic energy. Work, energy and power tuesday february 10th reading. The equation for power can be written as the rate of work. Physics 0303 nonconservative forces and conservation of energy. In grade 10, you saw that mechanical energy was conserved in the absence of nonconservative forces. A collision in which the total kinetic energy of the system is conserved is called elastic. Derive an equation for the potential energy of a spring, using hookes law and a forcedisplacement graph. There are many forms of energy, each involving both kinetic and potential energy.
Work done w is defined as the dot product of force f and displacement s. The rate at which energy is transferred is called power and the amount of energy that. 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 aeroplane flying, etc are among the most common examples that give us insight into the concept of work, power, and energy. Physics notes class 11 chapter 6 work, energy and power. When the pendulum is released, the potential energy is converted into kinetic energy as the pendulum bob descends under the i nfluence of gravity.
Learn science work power formulas with free interactive flashcards. Note if power is more, work is done fast and vice versa. 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 the capability of doing work is called energy.
The rate at which energy is transferred is called power and the amount of energy that is usefully transferred is called efficiency. Work, power and efficiency work, power and efficiency aqa. I will start the video by discussing calculation of dot product of two. Cbse class 11 physics work, energy and power formulas. For example, potential energy in the compressed spring, kinetic energy in the moving object, electromagnetic energy and heat are some of them. In a drought affected region she may be required to carry it over large. The bigger unit of power is kilowatt and represented by kw. 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. Work is said to be done when a force applied to an object moves that object. If youre seeing this message, it means were having trouble loading external resources on our website. 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. In physics, we can define energy as the capacity to do work. 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. The ratio of the kinetic energy gained to the work put in to lifting the cars is the efficiency kegpe of the system.
This summarizes most important formulae, concepts, in form of notes of work energy and power which you can read for jee, neet preparation. 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. When a net force does work on an object, then there is always a change in the kinetic energy of the object. The power rating energy per unit time of the stove can be calculated as. December 1996 subcourse overview this subcourse is designed to teach you to perform work, power and energy calculations for electrical circuits. If the puck slides twice as far, the friction does twice as much negative work. Energy is a key principle in physics, as it allows work to be done. The engine of your motorcycle works under this principle. The work w done by the net force on a particle equals the change in the particles kinetic energy ke.
Choose from 500 different sets of science work power formulas flashcards on quizlet. In the equation the mass is measured in kilograms and speed in ms. 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. 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. P power watts, w, js u voltage volts, v i current amperes, a r resistance ohms.
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. Work definition if an object moves in response to your application of a force, you have performed work. 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. Using the estimates of kinetic energy from problem 3, calculate the efficiency energy in vs. In other words, the work done is equal to the change in k. The energy dissipated in 60 seconds can be calculated. Work, energy and power definition, units, formula, examples. Work with the energy equation expressed in terms of heads, and use it to determine turbine power output and pumping power requirements. Physics 0302 potential energy and conservative forces. Work, energy and power definition, units, formula, examples, types.
Work done is measured in joules which has symbol j. The time integral of this scalar equation yields work from the instantaneous power, and kinetic energy from the scalar product of velocity and acceleration. The important notes of physics for work energy and power pdf download are available here for free. 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. 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. Energy energy is the quantity that can be used to perform work. Also, we know that when an object in motion strikes a stationary object, it can cause it to move. Energy transformed work done applied force x distance. Work can be used to understand the energy of many objects that experience forces. Hvac formulas ton of refrigeration the amount of heat required to melt a ton 2000 lbs. The further it moves under the influence of your force, the more work you perform. One example is the work required to stretch a spring. Energy cant be created or destroyed, it can only be changed from one type into another type. Power, the rate at which work is done or energy is transferred into or out of the system.
If youre behind a web filter, please make sure that the domains. A woman carrying water from a well to her house is said to be working. Work, energy and power formula list and important points in this video, we will revise the topic work, energy and power. These notes are prepared by some of the highly expert teachers. This also means the constraint forces do not add to the instantaneous power. This is the workenergy theorem or the relation between kinetic energy and work done. Work, energy and power physics neet class topperlearning. Work formula example of work types of energy power formula questions. An electric stove consumes 5 mj of energy from a 230 v power supply when turned on in 60 minutes. A farmer clearing weeds in his field is said to be working hard.
The force and the displacement must be parallel to one another in order for work to be done. 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. In the international system of units, the unit of power is the watt, equal to one joule per second. Kinetic energy is energy associated with motion, whether in a straight line of a circle.
The faster the pendulum bob moves, the greater its kinetic energy. Work, power and efficiency work, power and efficiency. Regarding the workenergy theorem it is worth noting that i if w net is positive, then k f k i positive, i. Class 11 physics revision notes for chapter 6 work, energy and power free pdf download. Distance, velocity, momentum, force, pressure, work and energy. 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. You can also call it as revision notes for work energy and power or cheat sheet of work energy and. Work and kinetic energy formula, definition, equation, videos. Chapter 6 work, kinetic energy and potential energy. We can calculate work by multiplying the force by the movement of the object.
Then the work done by the force is the component of f in the direction of motion. In physics, power is the rate of doing work or of transferring heat, i. Regarding the work energy theorem it is worth noting that i if w net is positive, then k f k i positive, i. 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. Work is said to be done when a force applied to an object moves that. Work and kinetic energy formula, definition, equation. 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.
Kinetic energy of an object is its capacity to put another object in motion. Jul 24, 2018 class 11 physics chapter 6 work, energy and power 03 work energy theorem iit jee neet duration. A powerful hoist needs energy fuel to keep on working. To register online physics tuitions on to clear your doubts from our expert teachers and solve the problems easily to score more marks in your cbse class 11 physics exam. 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. Power is the rate at which work is done or energy is transformed.
Work, energy and power class 11 notes physics chapter 6. 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. There are two types of energy, kinetic and potential. The fact that the work energy principle eliminates the constraint forces underlies lagrangian mechanics. It is measured by the product of the force and the distance moved in. It is measured by the product of the force and the distance moved in the direction of the force, i. Cascarano formula sheet physics 4a foothill college. Work, power, and energy are among the most important concepts of mechanics. Distance, velocity, momentum, force, pressure, work and. This section covers work, energy and power using maths. Class 11 physics revision notes for chapter 6 work. If positive work is done, then the object will gain energy. Solved examples on work, power and energy study material for.
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