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 W=1 J/s Power can also be expressed in as force F times velocity v. Since work is given by force times distance, W = Fd, and velocity is distance divided by time, v = d/t, then … Note that the form of energy (K.E and P.E) keeps on changing. ( If Fat supplies 3.8× J of energy on burning 1 kg fat which is converted to mechanical energy with a 20% efficiency rate. Make a list of questions which you were not able to solve in the first attempt or you took a long time solving them, after a week or two solve them again. Q1. Mathematically, Work done= Force * Distance. It was very useful ∴ 1 joule = 107erg Its dimensional formula is [ML2T-2]. We use cookies to provide you with a great experience and to help our website run effectively. Let 0 be the angle between the direction of force and the horizontal surface. Consider a force F acting on a body of mass m so that its velocity changes from u to v in travelling a distance s. Change in K.E of the body = Work done on the body by the net force. What is the difference between work energy and power? Ans. Grade 10. In a collision, sound may be ; produced. If under a constant force F a body is displaced through a distance s in time t, the power. Introduction: In physics, work is done on a body or by a body. Revision of Grade 9; States of Matter and the Kinetic Molecular Theory; Atomic structure; Periodic Table; Chemical Bonding; Transverse Pulses on a String or Spring; Waves - … If masses of A and B are equal, m1 = m2 = m, Inelastic colllision in one-dimension As the total linear momentum of the system reamins constant. How much fat will he use up considering the work done only when the weight is lifted up ? Due to configuration: A bullet is fired with a large velocity in a loaded gun due to the potential energy of the compressed spring in it. Concepts of work, kinetic energy and potential energy are discussed; these concepts are combined with the work-energy theorem to provide a convenient means of analyzing an object or system of objects moving between an initial and final state. The direction of force is along the string. Study the concept first and then start solving the question. Lect 03: Work-Energy Theorem. Class 6. The utmost collective illustrations that aid a concept of work, power and energy are a car in motion, bracing heavy objects, walking upstairs, an aeroplane flying and … Class 12. Tech Companion - A Complete pack to prepare for Engineering admissions, MBBS Companion - For NEET preparation and admission process, QnA - Get answers from students and experts, List of Pharmacy Colleges in India accepting GPAT. We often come across the word Power as well, for example, the bodybuilder hit the punching bag with huge power, so in a very crude way, we could say that the rate of doing work is power. When force acts along the direction of motion: Work done = Force x distance moved in direction of force, 2. Everybody knows that any type of motion requires energy. ∴U = mgh. It is represented by the letter W. It is a scalar quantity. Work and energy can be considered as two sides of the same coin. We could loosely correlate the physical definitions and physiological pictures. . Lots of love for all your team . Class 8. by a force (Both constant force and a variable force), conservation of mechanical energy, potential energy, kinetic energy, work-energy theorem, Potential energy of a spring, conservative and non-conservative forces, power, You will also come across a very important theorem of this chapter, known as a. theorem. Work Energy Theorem for a variable force: Consider a variable force$\vec { F }$ acting on a body of mass m and produces displacement $\vec { ds }$ in the same direction. You should also understand how scalar product of the two vectors is operated and what is the significance of scalar product. Conservation of energy links GPE, KE and work done. Springs A and B are identical except that A is stiffer than B, i.e., force constant kA> kg. It is measured by the product of the force and the distance moved in the direction of the force, i.e., W = F-S Cloudflare Ray ID: 5f0f9b2efd6cfe12 m1v1sinθ1, + m2v2sinθ2 = 0+0 = 0 By conservation of energy, ICSE Previous Year Question Papers Class 10, Concise Mathematics Class 10 ICSE Solutions, Concise Chemistry Class 10 ICSE Solutions, Concise Mathematics Class 9 ICSE Solutions, Reconstruction Essay | Essay on Reconstruction Essay for Students and Children in English, A Modest Proposal Essay | Essay on A Modest Proposal Essay for Students and Children in English, Causes of the Civil War Essay | Essay on Causes of the Civil War Essay for Students and Children in English, Sociological Imagination Essay | Essay on Sociological Imagination Essay for Students and Children in English, French Revolution Essay | Essay on French Revolution Essay for Students and Children in English, National Emblem Essay | Essay on National Emblem for Students and Children in English, Action Speak Louder than Words Essay | Essay on Action Speak Louder than Words Essay for Students and Children in English, Apoptosis Essay | Essay on Apoptosis Essay for Students and Children in English, Animal Right Essay | Essay on Animal Right for Students and Children in English, Plagiarism Essay | Essay on Plagiarism Essay for Students and Children in English, Cruelty to Animals Essay | Essay on Cruelty to Animals Essay for Students and Children in English, If θ = 0 then we get the first case where W = Fs (max. 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.