Use and define the units of work, energy and power. Jun 14, 2019 work, power and energy class 9 notes here we have provided summary and revision notes for class 9 science chapter 11. The value of kinetic energy is always positive or zero. Plus one physics notes chapter 6 work, energy and power. Work done by the force is positive if the angle between force and displacement is acute 0 power power is a rate of doing work. Class 11 physics chapter 6 work,energy and power 03 work energy theorem iit jee neet duration. Interpret the interrelation among work, energy and power with their unit and differentiate them.
In these notes a brief and simple explanation of all important topics is given which will help students make an. Notes for work energy and power this chapter is more of a concept based chapter there is very little to memorize, hence practice is the key here for getting a good hold on this chapter. Everybody knows that any type of motion requires energy. This gives us the concept of power or the rate of doing work. 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. For formulas, see formula for average power, definition of instantaneous power, and formula for. Icse class 10 physics revision notes chapter 2 work.
Important notes are also helpful for revision when you have less time and have to study many topics. Overview of work energy and power this chapter is very important because it will test your knowledge of the previous two chapters namely, kinematics, laws of motion and it will be also useful and crucial for you for solving questions from the next chapters namely system of particles, rotational motion and to some extent gravitation. Work is said to be done when the force is applied on a body and the body covers a certain distance. The unit of kinetic energy is the same as the unit of work, the joule j. Plus one physics notes chapter 6 work, energy and power a. Work done by the force is positive if the angle between force and displacement is acute 0 apr 22, 2019 workenergy theorem. Work and energy class 9 notes science mycbseguide cbse. Even if you wish to have an overview of a chapter, quick revision notes are.
An object which can do more work is said to have more energy and vice versa. Work done by the force is equal to the product of the force and the displacement of the object in the direction of force. Power, p work done,w time taken, t or power, p change of energy time taken, t 2. Work energy and power work done by force acting on a body is defined as the product of force and displacement of the body in the direction of the force. Cbse class 9 science work energy and power notes set b. Workenergy and power class 11 notes thus we have discussed three elementary topics on physics as students would have covered them during their high school days. A farmer ploughing the field, a construction worker carrying bricks, a student studying for a competitive examination, an artist painting a beautiful landscape, all. Work, energy and power examples a level maths revision. Work done by all the forces including the pseudo force change in kinetic energy in noninertial frame. The gravitational force and the force to stretch a spring are varying forces. Class 11 physics revision notes for chapter 6 work, energy and power free pdf download. Work, energy and power class 11 notes physics chapter 6.
If applied force f is not a constant force, then work done by this force in moving the body from position a to b will be. Work, energy and power study material for iit jee askiitians. Once we have an understanding of work, we can apply it to a new concept, energy, the measure of change within a system, and establish the workenergy theorem. Powerthe power is defined as the work done over a time period or rate of work done is known as the power. Cbse class 11 physics chapter 6 work, energy and power notes in pdf are available for free download in mycbseguide mobile app. Jan 19, 2020 this topic covers work, energy and power of o level physics. Potential energy the energy of configuration of a conservative system. Class 11 physics chapter 6 work, energy and power 04 potential energy iit jee neet youtube. Work is said to be done only when the force applied on a body makes the body move. Work and energy science class nine cbse subject notes. Class 11 physics chapter 6 work, energy and power 04 potential energy iit jee neet. Aug 22, 2017 iii at thermal power house, chemical energy of coal is changed into heat energy, which is futher converted into kinetic energy and electrical energy.
Definition, power can be defined as the rate at which work is done i. 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. Power is the rate of doing work, average p wt, where t is the. What is work energy and power get notes, books, formulas. Class 11 physics revision notes for chapter 6 work, energy. Work is done when a force is exerted on an object, and the object moves from one place to another.
Unit of power is the watt w, equal to an energy transfer rate of 1 joule per second. This topic covers work, energy and power of o level physics. Efficiency of a machine is a ratio of output work to input work. The terms work, energy and power are frequently used in everyday language.
Class 11 physics chapter 6 work,energy and power 04 potential energy iit jee neet youtube. Work, power, and energy are among the most important concepts of mechanics. Objects can possess energy in terms of the following. Regarding the workenergy theorem it is worth noting that i if w net is positive, then k f k i positive, i. Work, power and energy class 9 notes science chapter 11. Mar 16, 2018 cbse class 11 physics chapter 6 work, energy and power notes in pdf are available for free download in mycbseguide mobile app. Work is done on a body when a force on the body makes it move, similarly the body spends energy when it does work. In this article, we will learn all about the concept of work, power and energy. Work done w is defined as the dot product of force f and displacement s. The kinetic energy of an object can be related to its mass and velocity with the formula. Notes for work, energy and power chapter of class 11 physics. Work and energy can be considered as two sides of the same coin.
Work done is measured in joules which has symbol j. K, energy possessed by a body by virtue of its motion. A car moving, a rocket taking off, an aero plane flying, are a few of the events which take place regularly and can give us insight into the concept of work and energy. This section covers work, energy and power using maths. For example, a motorcycle has more energy than a bicycle. 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. Work, energy and power gcserevision, physics, forces. This is a complete set of notes of work energy and power which is a part of physics syllabus for neet, jee. Physicists mean something very specific when they talk about work. For a quantity of work w that is done in an amount of time t, the power done is, the unit for power is the watt w, which is equal to a joule per second, 1 w1 js power can also be expressed in as force f times velocity v. Class 9 science ncert in pdf chapter 11 work and energy.
Let us assume the variable force works from position x i to x f then according to the workenergy theorem the change in the kinetic energy is equals to the work done on by the variable force. Work, energy and power definition, units, formula, examples. The kinetic energy of an object is a scalar value, meaning it does not depend on the direction the object moves in. We talk about going to work, doing homework, working in class. Kerala plus one physics notes chapter 6 work, energy and power. Physics notes class 11 chapter 6 work, energy and power. It can also be defined as the rate of change of energy. Work done by a force in displacing a body is equal to change in its kinetic energy. Once we have an understanding of work, we can apply it to a new concept, energy, the measure of change within a system, and establish the work energy theorem. According to einstein, the mass can be transformed into energy and vice versa. As physics chapter 10 notes work, energy and power a. A farmer ploughing the field, a construction worker carrying bricks, a student studying for a competitive examination, an artist painting a beautiful landscape, all are said to be working.
Path independence property of conservative forces which states that the work done on any path between two given points is the same. Then the work done by the force is the component of f in the direction of motion. Class 11 physics chapter 6 work,energy and power 04 potential energy iit jee neet. The rate of converting energy or using energy is known as power. Where energy transferred by a force doing work, the energy transferred work done by the force. Power depends on the time taken and the work done as an analogy, people or engine with high power rating can get the work done in. If an object undergoes a displacement s along a straight line while acted on a force f. This is the name used to describe stored energy that an object has because of its position in. Finally, as we begin to explore more complex situations, we will examine work from a calculus standpoint, and. Notion of potential energy, potential energy of a spring, conservative forces. This cbse notes contains cbse key notes, cbse revision notes, short key notes, images, diagrams of the complete chapter 11 titled work, power and energy of science taught in class 9. You can also call it as revision notes for work energy and power or cheat sheet of work energy and. After completion of this lesson, student must be able to. In this topic we shall deal with these three important concepts of physics.
To register physics tuitions on to clear your doubts. In relation to energy, we can say that work is the amount of energy transferred or transformed, while power is the rate at which this energy is transferred or transformed. Work, energy and power definition, units, formula, examples, types. No machine is hundred percent efficient because there is always energy in the form of heat and sound. Work, energy and power are the most used terms in physics. The work accomplished is equal to the change in potential energy. Work done is generally referred in relation to the force applied while. The amount of work done per second, therefore indicates how powerful a machine is. Concepts of work, kinetic energy and potential energy are discussed. Important notes of physics for neet, jee for work energy and power are useful for all aspirants preparing for entrance exams including jee, neet. Aug 21, 2019 kerala plus one physics notes chapter 6 work, energy and power. When someone picks up an object, energy is transferred from the muscle to the object. Note that since power is the rate at which work is done, this defines power as the derivative of work with respect to time. We will also look at power, a practical concept that is derived from work.
Suppose a force f acts on a body, causing it to move in a particular direction. Work, power and energy class 9 notes here we have provided summary and revision notes for class 9 science chapter 11. This note provide us the information about work and its types. The best app for cbse students now provides work, energy and power class 11 notes latest chapter wise notes for quick preparation of cbse exams and school based annual examinations. Some questions of this chapter will involve the use of calculus and scalar product of vectors, hence keep your basics strong. This is the name used to describe stored energy that an object has because of its position in this case, higher above the surface of the earth. Thus work, energy and the power are related to each other.
Average power total work done or total energy usedtotal time taken. To lift an object slowly, a force equal to its weight mg is applied through a height h. Nov 29, 2017 in this article you will get cbse class 9 science, chapter notes on work and energy. Gravitational potential stores kinetic waves thermal stores elastic stores energy can be transferred between different. They are probably the first thing you learn in your physics class. Work, energy, and power notes for iit jee, download pdf. Work whenever a force acting on a body produces a change in the position of the body, work is said to be done by the force. Selina icse solutions for class 10 physics chapter 2 work, energy and power.
Work, energy and power tuesday february 10th reading. 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. This energy we get from the food which we eat and if work is done by machine. Power is the rate of doing work or the work done per second. Every year there are 12 questions asked from this topic. The revision notes covers all important formulas and concepts given in the chapter. A rollercoaster at the top of a slope has stored energy, which is called gravitational potential energy gpe, or sometimes potential energy pe. The greater the capacity of a body to do work, the greater the energy it has.
Cbse class 11 physics notes chapter 6 work energy and power. Cbse quick revision note for class9 science, chemistry, maths, biology and other subject are very helpful to revise the whole syllabus during exam days. Work, energy and power are some of the more important topics of mechanics in classical physics. A body which has the capacity to do work is said to posses energy.
Selina concise physics class 10 icse solutions work. We at byjus are of the opinion that proper guidance with the right textbooks is essential for students to succeed. Work done by a constant force work is a scalar quantity equal to the product of the displacement x and the component of the force f x in the direction of the displacement. Jul 25, 2019 work, energy, and power is an important topic from jee main jee advanced exam point of view. It shows the percentage of output work from the input work. Equivalent to american high school diploma subtopics. Energy is needed to make stationary objects move, change shape and warm them up. Work, energy and power class 8 science notes khullakitab.
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