...Energy, Work and power of the body All body activities including thinking, doing work, or keeping the body temp. constant involve energy changes, for example under resting(Basal)conditions the skeletal muscles and the heart using 25% of the body's energy ,another 19%is being used by the brain,10%is being used by the kidneys, and 27% is being used by the liver and the spleen. A small percent of about 5% of food energy being excreted in feces and urine. Extra food energy will be stored mainly as fat. External heat energy from environment can help maintain the body temp. , but it has no use in body function. Conservation of energy Change in the stored energy (i.e. food energy, body fat and the body heat) =Heat lost from the body + Work done Assumes that no food or drink is taken and no feces or urine is excreted during the interval of time considered. ●This is similar to the first law of thermodynamic:- ∆Q= ∆u + ∆w -1- ●Where ∆Q is the change of quantity of heat of the system. ● ● ∆u is the change in the internal or stored energy. ∆w is the work done. This can be written as ∆u= ∆Q - ∆w A body doing no work (∆w=0) and at constant temp. continues to lose heat to its surroundings, and ∆Q is negative. Therefore, ∆u is also negative, indicating a decrease in stored energy. The rate of change of their variables is just taken per unit time ( by dividing on ∆t) . ∆u / ∆t = ∆Q/∆t - ∆w/∆t The body's basic source of energy is the food energy; it must be chemically changed...
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...Organizational Behavior Human energy management is lacking in many companies, despite how it affects the overall performance in employees. Energy seems to be constantly drained, before, during and after work. It is affected by one’s relational, mental, physical and spiritual welfare. To find a way to retain or increase energy levels in the workplace, the frequency and correlation of micro-breaks (non-work and work related) taken by a group of knowledge workers with vitality and fatigue was investigated. Firstly, the methodology in using subjective vitality was largely accurate in measuring the complicated term. The accuracy of the seven-item subjective vitality scale used has been proven in a validation paper by Bostic, McGartland and Hood (2000). Results showed high factor loadings (>0.60), indicative that scale was consistent and reliable. However, the relationship between vitality and fatigue was not explained. If vitality is the enthusiasm that an employee has, the lack of it is due to fatigue – indication that they are merely flip sides. Improvements to data collection can be to use observational research by monitoring employees through a camera or to obtain colleagues’ assessment. While there is high cost in doing so, representative data can be obtained, eliminating the problem of inaccurate self-evaluation. The paper’s focus on strategies and breaks targeted at the individual may not be effective in boosting energies. The individual’s work is assumed to be the main...
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...Relationship among Force, Power, Work and Energy Force, work, energy and power are words used frequently in our everyday lives. What exactly do they mean? To put it simply, force is that which causes an object to move, while work is done when that force causes movement. Energy is the inherent ability of any object to do work, while power is the rate at which that work is done. Law of Conservation of Mechanical Energy Mechanical energy is stored in an object due to virtue of its motion. Potential energy and kinetic energy are the two types of mechanical energy, and the law of conservation of mechanical energy is associated with the conservation of these two energies in a system. Mechanical energy is basically a combination of potential and kinetic energy. Principle of Conservation of Mechanical Energy According to the law of conservation of mechanical energy, in an isolated system, that is, in the absence of non-conservative forces like friction, the initial total energy of the system equals to the total energy of the system. Simply stated, the total mechanical energy of a system is always constant (in case of absence of non-conservative forces). For instance, if a ball is rolled down a frictionless roller coaster, the initial and final energies remain constant. Conservative forces are those that don't depend on the path taken by an object. For example, gravity, spring and electrical forces are examples of mechanical energy. Conservation of Mechanical Energy Equation The quantitative...
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...With all this talk about fossil fuels polluting our earth, I have failed to demonstrate why solar energy is the superior "clean" alternative. Solar energy is a "clean" energy source because it takes the suns energy and converts it to usable energy without any pollution. The article "How Solar Power Works" explains this process. Solar panels contain cells made of silicon under a layer of glass for protection. These cells, when hit by sunlight, generate what they call electron activity. This electron activity is what creates the energy and that energy can then be stored in a battery or immediately used (Morris). Solar panels are not as "high tech" as I originally thought going into my research. This simple design eliminates the need for pollution....
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...Biomass Energy Biomass is a renewable energy and it is a natural material. A good example of biomass is wood, it gets burned and the energy can be used for cooking or heating. This essay will be covering aspects about biomass which include: What is biomass? How does biomass work? Different sources of biomass, advantages of biomass and disadvantages of biomass. What is biomass? Biomass is a renewable energy which is derived from living or recently living organisms that has been made into energy.Biomass energy has a life cycle and people are able to regrow theses plants. Biomass could be plants, animal waste, human waste or vegetables. The carbon used to make biomass grow is absorbed from the atmosphere as carbon dioxide (co2) using energy...
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...Summary of the Issue This article describes how human energy affects the work performance of an employee and how individuals sustain their energy during work. Common strategies used and related to increasing vitality and reducing fatigue were also discussed in the article. With low ability to sustain their energy over a long period of time, it might leads to consistent low-level of performance from the employee, which is not the interest of any organizations. This article brought up what organization can do to aid their employees to achieve full capacity in term of replenishing energy and removing hindering factors. In addition, it states that it is more common for individuals to use work-related strategies as compared to micro-breaks to be efficient in managing their energy. Hence, we will discuss in the report the reliability of the studies conducted. Theoretical Perspectives The effort-recovery model (Drenth, Thierry & De Wolff, 2001) states that human energy can be restored if an individual has attained the correct factors that help in recovery which includes disengaging from the activities that are straining. This brings about the perspectives that the employees might be facing difficulties in attaining full recovery from fatigue during work as they face working long hours and bringing work related stuff in their leisure time. Based on the five level of Maslow’s hierarchy of needs (Maslow, 1970), the most fundamental level of the pyramid consists of the basic physical...
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...Holt Physics—Chapter 5: Work and Energy Price I. Section 5.1—Work A. Definition of work 1. Work does not mean the same thing in Physics as it does in the everyday sense of the word. 2. Work is defined as a force causing a displacement. Work = force x displacement W = Fd 3. Work is NOT done on an object unless the displacement is greater than zero 4. The only forces that are considered to do work are those that are parallel to the displacement. 5. For this reason we use our trigonometric functions to calculate forces applied at an angle. Insert Fig 5-2 6. Note that Θ is the angle between the applied force and the displacement. 7. Work is described in Newtons x meters (force x displacement). The unit of work is the Joule (J) 8. 1 Newton meter = 1 Joule 9. Work is a vector with both direction AND magnitude. This means WORK CAN BE NEGATIVE! 10. Negative work is most commonly used to slow an object down or decrease its velocity. II. Section 5-2: Energy A. Kinetic Energy 1. Kinetic energy is associated with an object in motion. 2. Kinetic energy depends on speed and mass Kinetic Energy = ½mv2 3. Kinetic energy is a scalar and will use Joules as...
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...CHAPTER 2a ENERGY TRANSFER BY HEAT, WORK & MASS CONTENTS Forms of Energy Energy Transfer by Heat Energy Transfer by Work Mechanical Forms of Work The First Law of Thermodynamics Energy Balance for close system Energy Conversion Efficiencies FORMS OF ENERGY • Energy can exist in numerous forms such as thermal, mechanical, kinetic, potential, electric, magnetic, chemical, and nuclear, and their sum constitutes the total energy, E of a system. Thermodynamics deals only with the change of the total energy. Macroscopic forms of energy: Those a system possesses as a whole with respect to some outside reference frame, such as kinetic and potential energies. Microscopic forms of energy: Those related to the molecular structure of a system and the degree of the molecular activity. Internal energy, U: The sum of all the microscopic forms of energy. Kinetic energy, KE: The energy that a system possesses as a result of its motion relative to some reference frame. Potential energy, PE: The energy that a system possesses as a result of its elevation in a gravitational field. The macroscopic energy of an object changes with velocity and elevation. • • • • • • ENERGY EQUESIONS Kinetic energy Kinetic energy per unit mass Potential energy Most of the closed system remains stationary, so for that system; KE = PE = 0 Potential energy per unit mass Total energy of a system Energy of a system per unit mass Total energy per unit mass PROBLEM Determined the mass...
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...Chapter 2 ENERGY CONVERSION AND GENERAL ENERGY ANALYSIS W hether we realize it or not, energy is an important part of most aspects of daily life. The quality of life, and even its sustenance, depends on the availability of energy. Therefore, it is important to have a good understanding of the sources of energy, the conversion of energy from one form to another, and the ramifications of these conversions. Energy exists in numerous forms such as thermal, mechanical, electric, chemical, and nuclear. Even mass can be considered a form of energy. Energy can be transferred to or from a closed system (a fixed mass) in two distinct forms: heat and work. For control volumes, energy can also be transferred by mass flow. An energy transfer to or from a closed system is heat if it is caused by a temperature difference. Otherwise it is work, and it is caused by a force acting through a distance. We start this chapter with a discussion of various forms of energy and energy transfer by heat. We then introduce various forms of work and discuss energy transfer by work. We continue with developing a general intuitive expression for the first law of thermodynamics, also known as the conservation of energy principle, which is one of the most fundamental principles in nature, and we then demonstrate its use. Finally, we discuss the efficiencies of some familiar energy conversion processes, and examine the impact on energy conversion on the environment. Detailed treatments...
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...GRAPHS AND EQUATIONS (Using Work and Kinetic Energy) Joanne Gambon, Cheska Santos, Kim Urbano, Anna Veluz Abstract The researchers are tasked to perform an experiment involving force, work, and Kinetic energy. To perform the experiment, the researchers used graphing software to record their graphs, a dynamic cart, a pulley, ramp and a set of weights. The researchers started with gathering the data by attaching the cart to a pulley that is attached to a weight holder. Different weights are attached to determine its effect on the cart. The researchers then analyzed and computed the remaining data to get their desired variables. The researchers also graphed the obtained values for force vs. work and kinetic energy vs. work to compare the data. I. Introduction A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is an interaction between two objects, there is a force upon each of the objects. When the interaction ceases, the two objects no longer experience the force.[1] When a force acts upon an object to cause a displacement of the object, it is said that work was done upon the object. There are three key ingredients to work - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement.[2] Kinetic energy is the energy of motion. An object that has motion - whether it is vertical or horizontal...
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...cells that consist of animals, plants, and bacteria. They are biologically engineered yet composed of a multitude of chemical reactions. By examining organisms, their premise of living is based off of their ability to create energy. Chemistry is vital to the understanding of biology as seen with the chemical interactions that make up thermodynamics. Thermodynamics pertains to the change in energy and heat that occurs in all of matter. It is divided into categories of isolated...
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...Energy Agnese Strayer University Dr. Andrey R. Pavlov Science 110 April 21, 2012 We recognize energy through the concepts of force and motion. When work is done on an object, it gains energy. Energy is made of two types, potential energy which is stored energy and kinetic energy which consists of moving energy. Food is stored energy. It is stored as a chemical with potential energy. When your body uses that stored energy to do work, it then becomes kinetic energy.(Integrated Science, 2008) Any form of energy can be converted to another form. Most technological devices that we use are recognized as energy converters. Energy cannot be created, nor destroyed. This is the reason why it exists in many forms. For example, a light bulb converts electrical energy to radiant energy. It can come in various forms, mechanical, chemical, radiant, electrical, and nuclear. Thermodynamics is the study of energy being converted from one form to another. There are three laws of thermodynamics. The first law states that energy cannot be created or destroyed, but it can be converted from one form to another. The second law states that heat energy can be transferred only from body at high temperature to the body at lower temperature. Heat can only be moved from high to low without external work being performed. If you want to move the heat energy from low temperature reservoir to high temperature reservoir, then something external must intercept in order for that to work. (Definition...
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...of the laws governing the conversion of thermal energy into mechanical, electrical, or other forms of energy. It is a central branch of science that has important applications in chemistry, physics, biology, and engineering. What makes thermodynamics such a powerful tool? It is a completely logical discipline and can be applied without any sophisticated mathematical techniques. The immense practical value of thermodynamics lies in the fact that it systematizes the information obtained from experiments performed on systems and enables us to draw conclusions, without further experimentation, about other aspects of the same systems and about similar aspects of other systems. It allows us to predict whether a certain reaction will proceed and what the maximum yield might be. Thermodynamics is a macroscopic science concerning such properties as pressure, temperature, and volume. Unlike quantum mechanics, thermodynamics is not based on a specific molecular model, and therefore it is unelected by our changing concepts of atoms and molecules. Indeed, the major foundations of thermodynamics were laid long before detailed atomic theories became available. This fact is one of its major strengths. Furthermore, thermodynamics helps us predict the direction and extent of chemical reactions; it tells us nothing about the rate of a process. First Law of Thermodynamics Introduction The first law of conservation of energy states that energy is neither created nor destroyed. Thermodymics...
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...Thermodynamics: Chapter 6 * ability to do work * * energy used to take a mass and object with mass to move is called work * energy used ti cause the temp of an object to rise is called heat * energy from a battery * change chemical energy into heat or work * radiant energy comes form the sun and is earths primary energy source * thermal energy is energy associated with random motion of atoms and molecules * chemical energy is the energy stored within the bonds of chemical substances * nuclear energy is energy stored within collection nuetrons and protons * PE= ENERGY OF A OF POSITION * KE- ENERGY of of motion * energy released when bonds forms – bond energy (0-400 kj) * energy absorbed when bond breaks _bond energy (-i400 to -100) * when atoms in right distance 0 0, decrease in pe * completely p\apart and no affinity between the two * most important potential electrostatic energy in molecules is electros- associated with kollumbs law * si unit of energy is joule (J) 1 J- 1 kgm2/s2 * 1 cal in nutrition = 1 kcal in nutrition * 1 cal= 4.184 J * 1 cal = amount energy required to raise 1 g of water 1 C * ---- A food calorie is actually a kcal * the surroundings includes the universe * he system includes the molecules we want to study (here the hydrogen and oxygen molecules) * energy can enter or leave system as heat or as work done on a piston * Thermodynamics is the study of heat...
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...Thesis statement: Research shows that it would be beneficial for alternative energy sources to replace the use of fossil fuels, because they will provide a cleaner environment, are unlimited, and are more reliable. Annotated Bibliography Bhattacharjee, A. (2012). Everything You Need to Know About The Types of Renewable Energy. Retrieved January 23, 2016, from https://brainmass.com/ebooks/TypesOfRenewableEnergy The book gives the reader a clear and concise view of the alternative energy options. Each form of renewable energy is defined and talked about. The book discusses the history, current technology, and advantages as well as disadvantages of each form of renewable energy. The author, Anindita Bhattacha, has studied at the National Institute of Technology, Silchar, India as well as the New York Institute of Technology, USA. Her areas of specialty are earth sciences, engineering, and mathematics. Her education gives her credibility for this book. The book cites many professional and peer-reviewed articles and journals. These sources discuss the various forms of renewable energy and discuss both the advantages and disadvantages of many forms of renewable energy. These sources also discuss fossil fuel use, and how the use of these fuels impact our lives. The book will be used to discuss the relevant research on the benefits of renewable energy and how these sources are unlimited, and clean for the environment. Delavaripour, H., &...
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